Merge branch 'master' of https://github.com/PaddlePaddle/hapi

examples/bert/bert_classifier.py

@@ -103,7 +103,7 @@ def main():
         batch_size=config.batch_size,
         line_processor=mnli_line_processor)
 
-    dev_dataloader = BertDataLoader(
+    test_dataloader = BertDataLoader(
         "./data/glue_data/MNLI/dev_matched.tsv",
         tokenizer, ["contradiction", "entailment", "neutral"],
         max_seq_length=config.max_seq_len,

examples/bert_leveldb/bert_classifier.py

@@ -105,7 +105,7 @@ def main():
         mode="leveldb",
         phase="train")
 
-    dev_dataloader = BertDataLoader(
+    test_dataloader = BertDataLoader(
         "./data/glue_data/MNLI/dev_matched.tsv",
         tokenizer, ["contradiction", "entailment", "neutral"],
         max_seq_length=config.max_seq_len,

examples/image_classification/README.MD

@@ -85,8 +85,9 @@ CUDA_VISIBLE_DEVICES=0,1,2,3 python -m paddle.distributed.launch main.py --arch
 | [vgg16](https://paddle-hapi.bj.bcebos.com/models/vgg16.pdparams) | 71.92 | 90.65 | 
 | [mobilenet_v1](https://paddle-hapi.bj.bcebos.com/models/mobilenet_v1_x1.0.pdparams) | 71.16 | 89.89 | 
 | [mobilenet_v2](https://paddle-hapi.bj.bcebos.com/models/mobilenet_v2_x1.0.pdparams) | 72.30 | 90.74 | 
+| [darknet53](https://paddle-hapi.bj.bcebos.com/models/darknet53.pdparams) | 78.43 | 94.24 | 
 
-上述模型的复现参数请参考scripts下的脚本。
+上述部分模型的复现参数请参考scripts下的脚本。需要注意的是darknet要使用image size为256的输入来预测, 即```--image-size 256```
 
 
 ## 参考文献

examples/image_classification/imagenet_dataset.py

@@ -24,7 +24,11 @@ from paddle import fluid
 
 
 class ImageNetDataset(DatasetFolder):
-    def __init__(self, path, mode='train'):
+    def __init__(self,
+                 path,
+                 mode='train',
+                 image_size=224,
+                 resize_short_size=256):
         super(ImageNetDataset, self).__init__(path)
         self.mode = mode
 
@@ -32,13 +36,14 @@ class ImageNetDataset(DatasetFolder):
             mean=[123.675, 116.28, 103.53], std=[58.395, 57.120, 57.375])
         if self.mode == 'train':
             self.transform = transforms.Compose([
-                transforms.RandomResizedCrop(224),
+                transforms.RandomResizedCrop(image_size),
                 transforms.RandomHorizontalFlip(),
                 transforms.Permute(mode='CHW'), normalize
             ])
         else:
             self.transform = transforms.Compose([
-                transforms.Resize(256), transforms.CenterCrop(224),
+                transforms.Resize(resize_short_size),
+                transforms.CenterCrop(image_size),
                 transforms.Permute(mode='CHW'), normalize
             ])
 
@@ -46,7 +51,7 @@ class ImageNetDataset(DatasetFolder):
         img_path, label = self.samples[idx]
         img = cv2.imread(img_path).astype(np.float32)
         label = np.array([label])
-        return self.transform(img, label)
+        return self.transform(img), label
 
     def __len__(self):
         return len(self.samples)

examples/image_classification/main.py

@@ -18,8 +18,6 @@ from __future__ import print_function
 import argparse
 import contextlib
 import os
-import sys
-sys.path.append('../')
 
 import time
 import math
@@ -89,8 +87,16 @@ def main():
     labels = [Input([None, 1], 'int64', name='label')]
 
     train_dataset = ImageNetDataset(
-        os.path.join(FLAGS.data, 'train'), mode='train')
-    val_dataset = ImageNetDataset(os.path.join(FLAGS.data, 'val'), mode='val')
+        os.path.join(FLAGS.data, 'train'),
+        mode='train',
+        image_size=FLAGS.image_size,
+        resize_short_size=FLAGS.resize_short_size)
+
+    val_dataset = ImageNetDataset(
+        os.path.join(FLAGS.data, 'val'),
+        mode='val',
+        image_size=FLAGS.image_size,
+        resize_short_size=FLAGS.resize_short_size)
 
     optim = make_optimizer(
         np.ceil(
@@ -176,6 +182,13 @@ if __name__ == '__main__':
     parser.add_argument(
         "--weight-decay", default=1e-4, type=float, help="weight decay")
     parser.add_argument("--momentum", default=0.9, type=float, help="momentum")
+    parser.add_argument(
+        "--image-size", default=224, type=int, help="intput image size")
+    parser.add_argument(
+        "--resize-short-size",
+        default=256,
+        type=int,
+        help="short size of keeping ratio resize")
     FLAGS = parser.parse_args()
     assert FLAGS.data, "error: must provide data path"
     main()

examples/ocr/README.md

+简介
+--------
+本OCR任务是识别图片单行的字母信息，基于attention的seq2seq结构。 运行本目录下的程序示例需要使用PaddlePaddle develop最新版本。
+
+## 代码结构
+```
+.
+|-- data.py          # 数据读取
+|-- eval.py          # 评估脚本
+|-- images           # 测试图片
+|-- predict.py       # 预测脚本
+|-- seq2seq_attn.py  # 模型
+|-- train.py         # 训练脚本
+`-- utility.py       # 公共模块
+```
+
+## 训练/评估/预测流程
+
+- 设置GPU环境:
+
+```
+export CUDA_VISIBLE_DEVICES=0
+```
+
+- 训练
+
+```
+python train.py
+```
+
+更多参数可以通过`--help`查看。
+
+
+- 动静切换
+
+
+```
+python train.py --dynamic=True
+```
+
+
+- 评估
+
+```
+python eval.py --init_model=checkpoint/final
+```
+
+
+- 预测
+
+目前不支持动态图预测
+
+```
+python predict.py --init_model=checkpoint/final --image_path=images/ --dynamic=False --beam_size=3
+```
+
+预测结果如下:
+
+```
+Image 1: images/112_chubbiness_13557.jpg
+0: chubbines
+1: chubbiness
+2: chubbinesS
+Image 2: images/177_Interfiled_40185.jpg
+0: Interflied
+1: Interfiled
+2: InterfIled
+Image 3: images/325_dame_19109.jpg
+0: da
+1: damo
+2: dame
+Image 4: images/368_fixtures_29232.jpg
+0: firtures
+1: Firtures
+2: fixtures
+```

examples/ocr/data.py

+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import numpy as np
+from os import path
+import random
+import traceback
+import copy
+import math
+import tarfile
+from PIL import Image
+
+import logging
+logger = logging.getLogger(__name__)
+
+import paddle
+from paddle import fluid
+from paddle.fluid.dygraph.parallel import ParallelEnv
+
+DATA_MD5 = "7256b1d5420d8c3e74815196e58cdad5"
+DATA_URL = "http://paddle-ocr-data.bj.bcebos.com/data.tar.gz"
+CACHE_DIR_NAME = "attention_data"
+SAVED_FILE_NAME = "data.tar.gz"
+DATA_DIR_NAME = "data"
+TRAIN_DATA_DIR_NAME = "train_images"
+TEST_DATA_DIR_NAME = "test_images"
+TRAIN_LIST_FILE_NAME = "train.list"
+TEST_LIST_FILE_NAME = "test.list"
+
+
+class Resize(object):
+    def __init__(self, height=48):
+        self.interp = Image.NEAREST  # Image.ANTIALIAS
+        self.height = height
+
+    def __call__(self, samples):
+        shape = samples[0][0].size
+        for i in range(len(samples)):
+            im = samples[i][0]
+            im = im.resize((shape[0], self.height), self.interp)
+            samples[i][0] = im
+        return samples
+
+
+class Normalize(object):
+    def __init__(self,
+                 mean=[127.5],
+                 std=[1.0],
+                 scale=False,
+                 channel_first=True):
+        self.mean = mean
+        self.std = std
+        self.scale = scale
+        self.channel_first = channel_first
+        if not (isinstance(self.mean, list) and isinstance(self.std, list) and
+                isinstance(self.scale, bool)):
+            raise TypeError("{}: input type is invalid.".format(self))
+
+    def __call__(self, samples):
+        for i in range(len(samples)):
+            im = samples[i][0]
+            im = np.array(im).astype(np.float32, copy=False)
+            im = im[np.newaxis, ...]
+            mean = np.array(self.mean)[np.newaxis, np.newaxis, :]
+            std = np.array(self.std)[np.newaxis, np.newaxis, :]
+            if self.scale:
+                im = im / 255.0
+            #im -= mean
+            im -= 127.5
+            #im /= std
+            samples[i][0] = im
+        return samples
+
+
+class PadTarget(object):
+    def __init__(self, SOS=0, EOS=1):
+        self.SOS = SOS
+        self.EOS = EOS
+
+    def __call__(self, samples):
+        lens = np.array([len(s[1]) for s in samples], dtype="int64")
+        max_len = np.max(lens)
+        for i in range(len(samples)):
+            label = samples[i][1]
+            if max_len > len(label):
+                pad_label = label + [self.EOS] * (max_len - len(label))
+            else:
+                pad_label = label
+            samples[i][1] = np.array([self.SOS] + pad_label, dtype='int64')
+            # label_out
+            samples[i].append(np.array(pad_label + [self.EOS], dtype='int64'))
+            mask = np.zeros((max_len + 1)).astype('float32')
+            mask[:len(label) + 1] = 1.0
+            # mask
+            samples[i].append(np.array(mask, dtype='float32'))
+        return samples
+
+
+class BatchSampler(fluid.io.BatchSampler):
+    def __init__(self,
+                 dataset,
+                 batch_size,
+                 shuffle=False,
+                 drop_last=True,
+                 seed=None):
+        self._dataset = dataset
+        self._batch_size = batch_size
+        self._shuffle = shuffle
+        self._drop_last = drop_last
+        self._random = np.random
+        self._random.seed(seed)
+        self._nranks = ParallelEnv().nranks
+        self._local_rank = ParallelEnv().local_rank
+        self._device_id = ParallelEnv().dev_id
+        self._num_samples = int(
+            math.ceil(len(self._dataset) * 1.0 / self._nranks))
+        self._total_size = self._num_samples * self._nranks
+        self._epoch = 0
+
+    def __iter__(self):
+        infos = copy.copy(self._dataset._sample_infos)
+        skip_num = 0
+        if self._shuffle:
+            if self._batch_size == 1:
+                self._random.RandomState(self._epoch).shuffle(infos)
+            else:  # partial shuffle
+                infos = sorted(infos, key=lambda x: x.w)
+                skip_num = random.randint(1, 100)
+
+        infos = infos[skip_num:] + infos[:skip_num]
+        infos += infos[:(self._total_size - len(infos))]
+        last_size = self._total_size % (self._batch_size * self._nranks)
+        batches = []
+        for i in range(self._local_rank * self._batch_size,
+                       len(infos) - last_size,
+                       self._batch_size * self._nranks):
+            batches.append(infos[i:i + self._batch_size])
+
+        if (not self._drop_last) and last_size != 0:
+            last_local_size = last_size // self._nranks
+            last_infos = infos[len(infos) - last_size:]
+            start = self._local_rank * last_local_size
+            batches.append(last_infos[start:start + last_local_size])
+
+        if self._shuffle:
+            self._random.RandomState(self._epoch).shuffle(batches)
+            self._epoch += 1
+
+        for batch in batches:
+            batch_indices = [info.idx for info in batch]
+            yield batch_indices
+
+    def __len__(self):
+        if self._drop_last:
+            return self._total_size // self._batch_size
+        else:
+            return math.ceil(self._total_size / float(self._batch_size))
+
+
+class SampleInfo(object):
+    def __init__(self, idx, h, w, im_name, labels):
+        self.idx = idx
+        self.h = h
+        self.w = w
+        self.im_name = im_name
+        self.labels = labels
+
+
+class OCRDataset(paddle.io.Dataset):
+    def __init__(self, image_dir, anno_file):
+        self.image_dir = image_dir
+        self.anno_file = anno_file
+        self._sample_infos = []
+        with open(anno_file, 'r') as f:
+            for i, line in enumerate(f):
+                w, h, im_name, labels = line.strip().split(' ')
+                h, w = int(h), int(w)
+                labels = [int(c) for c in labels.split(',')]
+                self._sample_infos.append(SampleInfo(i, h, w, im_name, labels))
+
+    def __getitem__(self, idx):
+        info = self._sample_infos[idx]
+        im_name, labels = info.im_name, info.labels
+        image = Image.open(path.join(self.image_dir, im_name)).convert('L')
+        return [image, labels]
+
+    def __len__(self):
+        return len(self._sample_infos)
+
+
+def train(
+        root_dir=None,
+        images_dir=None,
+        anno_file=None,
+        shuffle=True, ):
+    if root_dir is None:
+        root_dir = download_data()
+    if images_dir is None:
+        images_dir = TRAIN_DATA_DIR_NAME
+    images_dir = path.join(root_dir, TRAIN_DATA_DIR_NAME)
+    if anno_file is None:
+        anno_file = TRAIN_LIST_FILE_NAME
+    anno_file = path.join(root_dir, TRAIN_LIST_FILE_NAME)
+    return OCRDataset(images_dir, anno_file)
+
+
+def test(
+        root_dir=None,
+        images_dir=None,
+        anno_file=None,
+        shuffle=True, ):
+    if root_dir is None:
+        root_dir = download_data()
+    if images_dir is None:
+        images_dir = TEST_DATA_DIR_NAME
+    images_dir = path.join(root_dir, TEST_DATA_DIR_NAME)
+    if anno_file is None:
+        anno_file = TEST_LIST_FILE_NAME
+    anno_file = path.join(root_dir, TEST_LIST_FILE_NAME)
+    return OCRDataset(images_dir, anno_file)
+
+
+def download_data():
+    '''Download train and test data.
+    '''
+    tar_file = paddle.dataset.common.download(
+        DATA_URL, CACHE_DIR_NAME, DATA_MD5, save_name=SAVED_FILE_NAME)
+    data_dir = path.join(path.dirname(tar_file), DATA_DIR_NAME)
+    if not path.isdir(data_dir):
+        t = tarfile.open(tar_file, "r:gz")
+        t.extractall(path=path.dirname(tar_file))
+        t.close()
+    return data_dir

examples/ocr/eval.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import print_function
+
+import argparse
+import functools
+
+import paddle.fluid.profiler as profiler
+import paddle.fluid as fluid
+
+from hapi.model import Input, set_device
+from hapi.vision.transforms import BatchCompose
+
+from utility import add_arguments, print_arguments
+from utility import SeqAccuracy, LoggerCallBack, SeqBeamAccuracy
+from utility import postprocess
+from seq2seq_attn import Seq2SeqAttModel, Seq2SeqAttInferModel, WeightCrossEntropy
+import data
+
+parser = argparse.ArgumentParser(description=__doc__)
+add_arg = functools.partial(add_arguments, argparser=parser)
+# yapf: disable
+add_arg('batch_size',        int,   32,                 "Minibatch size.")
+add_arg('test_images',       str,   None,               "The directory of images to be used for test.")
+add_arg('test_list',         str,   None,               "The list file of images to be used for training.")
+add_arg('init_model',        str,   'checkpoint/final', "The init model file of directory.")
+add_arg('use_gpu',           bool,  True,               "Whether use GPU to train.")
+add_arg('encoder_size',      int,   200,                "Encoder size.")
+add_arg('decoder_size',      int,   128,                "Decoder size.")
+add_arg('embedding_dim',     int,   128,                "Word vector dim.")
+add_arg('num_classes',       int,   95,                 "Number classes.")
+add_arg('beam_size',         int,   0,                  "If set beam size, will use beam search.")
+add_arg('dynamic',           bool,  False,              "Whether to use dygraph.")
+# yapf: enable
+
+
+def main(FLAGS):
+    device = set_device("gpu" if FLAGS.use_gpu else "cpu")
+    fluid.enable_dygraph(device) if FLAGS.dynamic else None
+    model = Seq2SeqAttModel(
+        encoder_size=FLAGS.encoder_size,
+        decoder_size=FLAGS.decoder_size,
+        emb_dim=FLAGS.embedding_dim,
+        num_classes=FLAGS.num_classes)
+
+    # yapf: disable
+    inputs = [
+        Input([None, 1, 48, 384], "float32", name="pixel"),
+        Input([None, None], "int64", name="label_in")
+    ]
+    labels = [
+        Input([None, None], "int64", name="label_out"),
+        Input([None, None], "float32", name="mask")
+    ]
+    # yapf: enable
+
+    model.prepare(
+        loss_function=WeightCrossEntropy(),
+        metrics=SeqAccuracy(),
+        inputs=inputs,
+        labels=labels,
+        device=device)
+    model.load(FLAGS.init_model)
+
+    test_dataset = data.test()
+    test_collate_fn = BatchCompose(
+        [data.Resize(), data.Normalize(), data.PadTarget()])
+    test_sampler = data.BatchSampler(
+        test_dataset,
+        batch_size=FLAGS.batch_size,
+        drop_last=False,
+        shuffle=False)
+    test_loader = fluid.io.DataLoader(
+        test_dataset,
+        batch_sampler=test_sampler,
+        places=device,
+        num_workers=0,
+        return_list=True,
+        collate_fn=test_collate_fn)
+
+    model.evaluate(
+        eval_data=test_loader,
+        callbacks=[LoggerCallBack(10, 2, FLAGS.batch_size)])
+
+
+def beam_search(FLAGS):
+    device = set_device("gpu" if FLAGS.use_gpu else "cpu")
+    fluid.enable_dygraph(device) if FLAGS.dynamic else None
+    model = Seq2SeqAttInferModel(
+        encoder_size=FLAGS.encoder_size,
+        decoder_size=FLAGS.decoder_size,
+        emb_dim=FLAGS.embedding_dim,
+        num_classes=FLAGS.num_classes,
+        beam_size=FLAGS.beam_size)
+
+    inputs = [
+        Input(
+            [None, 1, 48, 384], "float32", name="pixel"), Input(
+                [None, None], "int64", name="label_in")
+    ]
+    labels = [
+        Input(
+            [None, None], "int64", name="label_out"), Input(
+                [None, None], "float32", name="mask")
+    ]
+    model.prepare(
+        loss_function=None,
+        metrics=SeqBeamAccuracy(),
+        inputs=inputs,
+        labels=labels,
+        device=device)
+    model.load(FLAGS.init_model)
+
+    test_dataset = data.test()
+    test_collate_fn = BatchCompose(
+        [data.Resize(), data.Normalize(), data.PadTarget()])
+    test_sampler = data.BatchSampler(
+        test_dataset,
+        batch_size=FLAGS.batch_size,
+        drop_last=False,
+        shuffle=False)
+    test_loader = fluid.io.DataLoader(
+        test_dataset,
+        batch_sampler=test_sampler,
+        places=device,
+        num_workers=0,
+        return_list=True,
+        collate_fn=test_collate_fn)
+
+    model.evaluate(
+        eval_data=test_loader,
+        callbacks=[LoggerCallBack(10, 2, FLAGS.batch_size)])
+
+
+if __name__ == '__main__':
+    FLAGS = parser.parse_args()
+    print_arguments(FLAGS)
+    if FLAGS.beam_size:
+        beam_search(FLAGS)
+    else:
+        main(FLAGS)

examples/ocr/predict.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import print_function
+
+import os
+import sys
+import random
+import numpy as np
+
+import argparse
+import functools
+from PIL import Image
+
+import paddle.fluid.profiler as profiler
+import paddle.fluid as fluid
+
+from hapi.model import Input, set_device
+from hapi.datasets.folder import ImageFolder
+from hapi.vision.transforms import BatchCompose
+
+from utility import add_arguments, print_arguments
+from utility import postprocess, index2word
+from seq2seq_attn import Seq2SeqAttInferModel, WeightCrossEntropy
+import data
+
+parser = argparse.ArgumentParser(description=__doc__)
+add_arg = functools.partial(add_arguments, argparser=parser)
+# yapf: disable
+add_arg('batch_size',        int,   1,       "Minibatch size.")
+add_arg('image_path',        str,   None,    "The directory of images to be used for test.")
+add_arg('init_model',        str,   None,    "The init model file of directory.")
+add_arg('use_gpu',           bool,  True,    "Whether use GPU to train.")
+# model hyper paramters
+add_arg('encoder_size',      int,   200,     "Encoder size.")
+add_arg('decoder_size',      int,   128,     "Decoder size.")
+add_arg('embedding_dim',     int,   128,     "Word vector dim.")
+add_arg('num_classes',       int,   95,      "Number classes.")
+add_arg('beam_size',         int,   3,       "Beam size for beam search.")
+add_arg('dynamic',           bool,  False,   "Whether to use dygraph.")
+# yapf: enable
+
+
+def main(FLAGS):
+    device = set_device("gpu" if FLAGS.use_gpu else "cpu")
+    fluid.enable_dygraph(device) if FLAGS.dynamic else None
+    model = Seq2SeqAttInferModel(
+        encoder_size=FLAGS.encoder_size,
+        decoder_size=FLAGS.decoder_size,
+        emb_dim=FLAGS.embedding_dim,
+        num_classes=FLAGS.num_classes,
+        beam_size=FLAGS.beam_size)
+
+    inputs = [Input([None, 1, 48, 384], "float32", name="pixel"), ]
+
+    model.prepare(inputs=inputs, device=device)
+    model.load(FLAGS.init_model)
+
+    fn = lambda p: Image.open(p).convert('L')
+    test_dataset = ImageFolder(FLAGS.image_path, loader=fn)
+    test_collate_fn = BatchCompose([data.Resize(), data.Normalize()])
+    test_loader = fluid.io.DataLoader(
+        test_dataset,
+        places=device,
+        num_workers=0,
+        return_list=True,
+        collate_fn=test_collate_fn)
+
+    samples = test_dataset.samples
+    #outputs = model.predict(test_loader)
+    ins_id = 0
+    for image, in test_loader:
+        image = image if FLAGS.dynamic else image[0]
+        pred = model.test_batch([image])[0]
+        pred = pred[:, :, np.newaxis] if len(pred.shape) == 2 else pred
+        pred = np.transpose(pred, [0, 2, 1])
+        for ins in pred:
+            impath = samples[ins_id]
+            ins_id += 1
+            print('Image {}: {}'.format(ins_id, impath))
+            for beam_idx, beam in enumerate(ins):
+                id_list = postprocess(beam)
+                word_list = index2word(id_list)
+                sequence = "".join(word_list)
+                print('{}: {}'.format(beam_idx, sequence))
+
+
+if __name__ == '__main__':
+    FLAGS = parser.parse_args()
+    print_arguments(FLAGS)
+    main(FLAGS)

examples/ocr/seq2seq_attn.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import print_function
+
+import numpy as np
+
+import paddle.fluid as fluid
+import paddle.fluid.layers as layers
+from paddle.fluid.layers import BeamSearchDecoder
+
+from hapi.text import RNNCell, RNN, DynamicDecode
+from hapi.model import Model, Loss
+
+
+class ConvBNPool(fluid.dygraph.Layer):
+    def __init__(self,
+                 in_ch,
+                 out_ch,
+                 act="relu",
+                 is_test=False,
+                 pool=True,
+                 use_cudnn=True):
+        super(ConvBNPool, self).__init__()
+        self.pool = pool
+
+        filter_size = 3
+        std = (2.0 / (filter_size**2 * in_ch))**0.5
+        param_0 = fluid.ParamAttr(
+            initializer=fluid.initializer.Normal(0.0, std))
+
+        std = (2.0 / (filter_size**2 * out_ch))**0.5
+        param_1 = fluid.ParamAttr(
+            initializer=fluid.initializer.Normal(0.0, std))
+
+        self.conv0 = fluid.dygraph.Conv2D(
+            in_ch,
+            out_ch,
+            3,
+            padding=1,
+            param_attr=param_0,
+            bias_attr=False,
+            act=None,
+            use_cudnn=use_cudnn)
+        self.bn0 = fluid.dygraph.BatchNorm(out_ch, act=act)
+        self.conv1 = fluid.dygraph.Conv2D(
+            out_ch,
+            out_ch,
+            filter_size=3,
+            padding=1,
+            param_attr=param_1,
+            bias_attr=False,
+            act=None,
+            use_cudnn=use_cudnn)
+        self.bn1 = fluid.dygraph.BatchNorm(out_ch, act=act)
+
+        if self.pool:
+            self.pool = fluid.dygraph.Pool2D(
+                pool_size=2,
+                pool_type='max',
+                pool_stride=2,
+                use_cudnn=use_cudnn,
+                ceil_mode=True)
+
+    def forward(self, inputs):
+        out = self.conv0(inputs)
+        out = self.bn0(out)
+        out = self.conv1(out)
+        out = self.bn1(out)
+        if self.pool:
+            out = self.pool(out)
+        return out
+
+
+class CNN(fluid.dygraph.Layer):
+    def __init__(self, in_ch=1, is_test=False):
+        super(CNN, self).__init__()
+        self.conv_bn1 = ConvBNPool(in_ch, 16)
+        self.conv_bn2 = ConvBNPool(16, 32)
+        self.conv_bn3 = ConvBNPool(32, 64)
+        self.conv_bn4 = ConvBNPool(64, 128, pool=False)
+
+    def forward(self, inputs):
+        conv = self.conv_bn1(inputs)
+        conv = self.conv_bn2(conv)
+        conv = self.conv_bn3(conv)
+        conv = self.conv_bn4(conv)
+        return conv
+
+
+class GRUCell(RNNCell):
+    def __init__(self,
+                 input_size,
+                 hidden_size,
+                 param_attr=None,
+                 bias_attr=None,
+                 gate_activation='sigmoid',
+                 candidate_activation='tanh',
+                 origin_mode=False):
+        super(GRUCell, self).__init__()
+        self.hidden_size = hidden_size
+        self.fc_layer = fluid.dygraph.Linear(
+            input_size,
+            hidden_size * 3,
+            param_attr=param_attr,
+            bias_attr=False)
+
+        self.gru_unit = fluid.dygraph.GRUUnit(
+            hidden_size * 3,
+            param_attr=param_attr,
+            bias_attr=bias_attr,
+            activation=candidate_activation,
+            gate_activation=gate_activation,
+            origin_mode=origin_mode)
+
+    def forward(self, inputs, states):
+        # step_outputs, new_states = cell(step_inputs, states)
+        # for GRUCell, `step_outputs` and `new_states` both are hidden
+        x = self.fc_layer(inputs)
+        hidden, _, _ = self.gru_unit(x, states)
+        return hidden, hidden
+
+    @property
+    def state_shape(self):
+        return [self.hidden_size]
+
+
+class Encoder(fluid.dygraph.Layer):
+    def __init__(
+            self,
+            in_channel=1,
+            rnn_hidden_size=200,
+            decoder_size=128,
+            is_test=False, ):
+        super(Encoder, self).__init__()
+        self.rnn_hidden_size = rnn_hidden_size
+
+        self.backbone = CNN(in_ch=in_channel, is_test=is_test)
+
+        para_attr = fluid.ParamAttr(
+            initializer=fluid.initializer.Normal(0.0, 0.02))
+        bias_attr = fluid.ParamAttr(
+            initializer=fluid.initializer.Normal(0.0, 0.02), learning_rate=2.0)
+        self.gru_fwd = RNN(cell=GRUCell(
+            input_size=128 * 6,
+            hidden_size=rnn_hidden_size,
+            param_attr=para_attr,
+            bias_attr=bias_attr,
+            candidate_activation='relu'),
+                           is_reverse=False,
+                           time_major=False)
+        self.gru_bwd = RNN(cell=GRUCell(
+            input_size=128 * 6,
+            hidden_size=rnn_hidden_size,
+            param_attr=para_attr,
+            bias_attr=bias_attr,
+            candidate_activation='relu'),
+                           is_reverse=True,
+                           time_major=False)
+        self.encoded_proj_fc = fluid.dygraph.Linear(
+            rnn_hidden_size * 2, decoder_size, bias_attr=False)
+
+    def forward(self, inputs):
+        conv_features = self.backbone(inputs)
+        conv_features = fluid.layers.transpose(
+            conv_features, perm=[0, 3, 1, 2])
+
+        n, w, c, h = conv_features.shape
+        seq_feature = fluid.layers.reshape(conv_features, [0, -1, c * h])
+
+        gru_fwd, _ = self.gru_fwd(seq_feature)
+        gru_bwd, _ = self.gru_bwd(seq_feature)
+
+        encoded_vector = fluid.layers.concat(input=[gru_fwd, gru_bwd], axis=2)
+        encoded_proj = self.encoded_proj_fc(encoded_vector)
+        return gru_bwd, encoded_vector, encoded_proj
+
+
+class Attention(fluid.dygraph.Layer):
+    """
+    Neural Machine Translation by Jointly Learning to Align and Translate.
+    https://arxiv.org/abs/1409.0473
+    """
+
+    def __init__(self, decoder_size):
+        super(Attention, self).__init__()
+        self.fc1 = fluid.dygraph.Linear(
+            decoder_size, decoder_size, bias_attr=False)
+        self.fc2 = fluid.dygraph.Linear(decoder_size, 1, bias_attr=False)
+
+    def forward(self, encoder_vec, encoder_proj, decoder_state):
+        # alignment model, single-layer multilayer perceptron
+        decoder_state = self.fc1(decoder_state)
+        decoder_state = fluid.layers.unsqueeze(decoder_state, [1])
+
+        e = fluid.layers.elementwise_add(encoder_proj, decoder_state)
+        e = fluid.layers.tanh(e)
+
+        att_scores = self.fc2(e)
+        att_scores = fluid.layers.squeeze(att_scores, [2])
+        att_scores = fluid.layers.softmax(att_scores)
+
+        context = fluid.layers.elementwise_mul(
+            x=encoder_vec, y=att_scores, axis=0)
+        context = fluid.layers.reduce_sum(context, dim=1)
+        return context
+
+
+class DecoderCell(RNNCell):
+    def __init__(self, encoder_size=200, decoder_size=128):
+        super(DecoderCell, self).__init__()
+        self.attention = Attention(decoder_size)
+        self.gru_cell = GRUCell(
+            input_size=encoder_size * 2 + decoder_size,
+            hidden_size=decoder_size)
+
+    def forward(self, current_word, states, encoder_vec, encoder_proj):
+        context = self.attention(encoder_vec, encoder_proj, states)
+        decoder_inputs = fluid.layers.concat([current_word, context], axis=1)
+        hidden, _ = self.gru_cell(decoder_inputs, states)
+        return hidden, hidden
+
+
+class Decoder(fluid.dygraph.Layer):
+    def __init__(self, num_classes, emb_dim, encoder_size, decoder_size):
+        super(Decoder, self).__init__()
+        self.decoder_attention = RNN(DecoderCell(encoder_size, decoder_size))
+        self.fc = fluid.dygraph.Linear(
+            decoder_size, num_classes + 2, act='softmax')
+
+    def forward(self, target, initial_states, encoder_vec, encoder_proj):
+        out, _ = self.decoder_attention(
+            target,
+            initial_states=initial_states,
+            encoder_vec=encoder_vec,
+            encoder_proj=encoder_proj)
+        pred = self.fc(out)
+        return pred
+
+
+class Seq2SeqAttModel(Model):
+    def __init__(
+            self,
+            in_channle=1,
+            encoder_size=200,
+            decoder_size=128,
+            emb_dim=128,
+            num_classes=None, ):
+        super(Seq2SeqAttModel, self).__init__()
+        self.encoder = Encoder(in_channle, encoder_size, decoder_size)
+        self.fc = fluid.dygraph.Linear(
+            input_dim=encoder_size,
+            output_dim=decoder_size,
+            bias_attr=False,
+            act='relu')
+        self.embedding = fluid.dygraph.Embedding(
+            [num_classes + 2, emb_dim], dtype='float32')
+        self.decoder = Decoder(num_classes, emb_dim, encoder_size,
+                               decoder_size)
+
+    def forward(self, inputs, target):
+        gru_backward, encoded_vector, encoded_proj = self.encoder(inputs)
+        decoder_boot = self.fc(gru_backward[:, 0])
+        trg_embedding = self.embedding(target)
+        prediction = self.decoder(trg_embedding, decoder_boot, encoded_vector,
+                                  encoded_proj)
+        return prediction
+
+
+class Seq2SeqAttInferModel(Seq2SeqAttModel):
+    def __init__(
+            self,
+            in_channle=1,
+            encoder_size=200,
+            decoder_size=128,
+            emb_dim=128,
+            num_classes=None,
+            beam_size=0,
+            bos_id=0,
+            eos_id=1,
+            max_out_len=20, ):
+        super(Seq2SeqAttInferModel, self).__init__(
+            in_channle, encoder_size, decoder_size, emb_dim, num_classes)
+        self.beam_size = beam_size
+        # dynamic decoder for inference
+        decoder = BeamSearchDecoder(
+            self.decoder.decoder_attention.cell,
+            start_token=bos_id,
+            end_token=eos_id,
+            beam_size=beam_size,
+            embedding_fn=self.embedding,
+            output_fn=self.decoder.fc)
+        self.infer_decoder = DynamicDecode(
+            decoder, max_step_num=max_out_len, is_test=True)
+
+    def forward(self, inputs, *args):
+        gru_backward, encoded_vector, encoded_proj = self.encoder(inputs)
+        decoder_boot = self.fc(gru_backward[:, 0])
+
+        if self.beam_size:
+            # Tile the batch dimension with beam_size
+            encoded_vector = BeamSearchDecoder.tile_beam_merge_with_batch(
+                encoded_vector, self.beam_size)
+            encoded_proj = BeamSearchDecoder.tile_beam_merge_with_batch(
+                encoded_proj, self.beam_size)
+        # dynamic decoding with beam search
+        rs, _ = self.infer_decoder(
+            inits=decoder_boot,
+            encoder_vec=encoded_vector,
+            encoder_proj=encoded_proj)
+        return rs
+
+
+class WeightCrossEntropy(Loss):
+    def __init__(self):
+        super(WeightCrossEntropy, self).__init__(average=False)
+
+    def forward(self, outputs, labels):
+        predict, (label, mask) = outputs[0], labels
+        loss = layers.cross_entropy(predict, label=label)
+        loss = layers.elementwise_mul(loss, mask, axis=0)
+        loss = layers.reduce_sum(loss)
+        return loss

examples/ocr/train.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import print_function
+
+import os
+import sys
+import random
+import numpy as np
+
+import argparse
+import functools
+
+import paddle.fluid.profiler as profiler
+import paddle.fluid as fluid
+
+from hapi.model import Input, set_device
+from hapi.vision.transforms import BatchCompose
+
+from utility import add_arguments, print_arguments
+from utility import SeqAccuracy, LoggerCallBack
+from seq2seq_attn import Seq2SeqAttModel, WeightCrossEntropy
+import data
+
+parser = argparse.ArgumentParser(description=__doc__)
+add_arg = functools.partial(add_arguments, argparser=parser)
+# yapf: disable
+add_arg('batch_size',        int,   32,           "Minibatch size.")
+add_arg('epoch',             int,   30,           "Epoch number.")
+add_arg('num_workers',       int,   0,            "workers number.")
+add_arg('lr',                float, 0.001,        "Learning rate.")
+add_arg('lr_decay_strategy', str,   "",           "Learning rate decay strategy.")
+add_arg('checkpoint_path',   str,   "checkpoint", "The directory the model to be saved to.")
+add_arg('train_images',      str,   None,         "The directory of images to be used for training.")
+add_arg('train_list',        str,   None,         "The list file of images to be used for training.")
+add_arg('test_images',       str,   None,         "The directory of images to be used for test.")
+add_arg('test_list',         str,   None,         "The list file of images to be used for training.")
+add_arg('resume_path',       str,   None,         "The init model file of directory.")
+add_arg('use_gpu',           bool,  True,         "Whether use GPU to train.")
+# model hyper paramters
+add_arg('encoder_size',      int,   200,     "Encoder size.")
+add_arg('decoder_size',      int,   128,     "Decoder size.")
+add_arg('embedding_dim',     int,   128,     "Word vector dim.")
+add_arg('num_classes',       int,   95,     "Number classes.")
+add_arg('gradient_clip',     float, 5.0,     "Gradient clip value.")
+add_arg('dynamic',           bool,  False,      "Whether to use dygraph.")
+# yapf: enable
+
+
+def main(FLAGS):
+    device = set_device("gpu" if FLAGS.use_gpu else "cpu")
+    fluid.enable_dygraph(device) if FLAGS.dynamic else None
+
+    model = Seq2SeqAttModel(
+        encoder_size=FLAGS.encoder_size,
+        decoder_size=FLAGS.decoder_size,
+        emb_dim=FLAGS.embedding_dim,
+        num_classes=FLAGS.num_classes)
+
+    lr = FLAGS.lr
+    if FLAGS.lr_decay_strategy == "piecewise_decay":
+        learning_rate = fluid.layers.piecewise_decay(
+            [200000, 250000], [lr, lr * 0.1, lr * 0.01])
+    else:
+        learning_rate = lr
+    grad_clip = fluid.clip.GradientClipByGlobalNorm(FLAGS.gradient_clip)
+    optimizer = fluid.optimizer.Adam(
+        learning_rate=learning_rate,
+        parameter_list=model.parameters(),
+        grad_clip=grad_clip)
+
+    # yapf: disable
+    inputs = [
+        Input([None,1,48,384], "float32", name="pixel"),
+        Input([None, None], "int64", name="label_in"),
+    ]
+    labels = [
+        Input([None, None], "int64", name="label_out"),
+        Input([None, None], "float32", name="mask"),
+    ]
+    # yapf: enable
+
+    model.prepare(
+        optimizer,
+        WeightCrossEntropy(),
+        SeqAccuracy(),
+        inputs=inputs,
+        labels=labels)
+
+    train_dataset = data.train()
+    train_collate_fn = BatchCompose(
+        [data.Resize(), data.Normalize(), data.PadTarget()])
+    train_sampler = data.BatchSampler(
+        train_dataset, batch_size=FLAGS.batch_size, shuffle=True)
+    train_loader = fluid.io.DataLoader(
+        train_dataset,
+        batch_sampler=train_sampler,
+        places=device,
+        num_workers=FLAGS.num_workers,
+        return_list=True,
+        collate_fn=train_collate_fn)
+    test_dataset = data.test()
+    test_collate_fn = BatchCompose(
+        [data.Resize(), data.Normalize(), data.PadTarget()])
+    test_sampler = data.BatchSampler(
+        test_dataset,
+        batch_size=FLAGS.batch_size,
+        drop_last=False,
+        shuffle=False)
+    test_loader = fluid.io.DataLoader(
+        test_dataset,
+        batch_sampler=test_sampler,
+        places=device,
+        num_workers=0,
+        return_list=True,
+        collate_fn=test_collate_fn)
+
+    model.fit(train_data=train_loader,
+              eval_data=test_loader,
+              epochs=FLAGS.epoch,
+              save_dir=FLAGS.checkpoint_path,
+              callbacks=[LoggerCallBack(10, 2, FLAGS.batch_size)])
+
+
+if __name__ == '__main__':
+    FLAGS = parser.parse_args()
+    print_arguments(FLAGS)
+    main(FLAGS)

examples/ocr/utility.py

+"""Contains common utility functions."""
+#  Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+#Licensed under the Apache License, Version 2.0 (the "License");
+#you may not use this file except in compliance with the License.
+#You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+#Unless required by applicable law or agreed to in writing, software
+#distributed under the License is distributed on an "AS IS" BASIS,
+#WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#See the License for the specific language governing permissions and
+#limitations under the License.
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+import distutils.util
+import numpy as np
+import paddle.fluid as fluid
+import six
+
+from hapi.metrics import Metric
+from hapi.callbacks import ProgBarLogger
+
+
+def print_arguments(args):
+    """Print argparse's arguments.
+
+    Usage:
+
+    .. code-block:: python
+
+        parser = argparse.ArgumentParser()
+        parser.add_argument("name", default="Jonh", type=str, help="User name.")
+        args = parser.parse_args()
+        print_arguments(args)
+
+    :param args: Input argparse.Namespace for printing.
+    :type args: argparse.Namespace
+    """
+    print("-----------  Configuration Arguments -----------")
+    for arg, value in sorted(six.iteritems(vars(args))):
+        print("%s: %s" % (arg, value))
+    print("------------------------------------------------")
+
+
+def add_arguments(argname, type, default, help, argparser, **kwargs):
+    """Add argparse's argument.
+
+    Usage:
+
+    .. code-block:: python
+
+        parser = argparse.ArgumentParser()
+        add_argument("name", str, "Jonh", "User name.", parser)
+        args = parser.parse_args()
+    """
+    type = distutils.util.strtobool if type == bool else type
+    argparser.add_argument(
+        "--" + argname,
+        default=default,
+        type=type,
+        help=help + ' Default: %(default)s.',
+        **kwargs)
+
+
+class SeqAccuracy(Metric):
+    def __init__(self, name=None, *args, **kwargs):
+        super(SeqAccuracy, self).__init__(*args, **kwargs)
+        self._name = 'seq_acc'
+        self.reset()
+
+    def add_metric_op(self, output, label, mask, *args, **kwargs):
+        pred = fluid.layers.flatten(output, axis=2)
+        score, topk = fluid.layers.topk(pred, 1)
+        return topk, label, mask
+
+    def update(self, topk, label, mask, *args, **kwargs):
+        topk = topk.reshape(label.shape[0], -1)
+        seq_len = np.sum(mask, -1)
+        acc = 0
+        for i in range(label.shape[0]):
+            l = int(seq_len[i] - 1)
+            pred = topk[i][:l - 1]
+            ref = label[i][:l - 1]
+            if np.array_equal(pred, ref):
+                self.total += 1
+                acc += 1
+            self.count += 1
+        return float(acc) / label.shape[0]
+
+    def reset(self):
+        self.total = 0.
+        self.count = 0.
+
+    def accumulate(self):
+        return float(self.total) / self.count
+
+    def name(self):
+        return self._name
+
+
+class LoggerCallBack(ProgBarLogger):
+    def __init__(self, log_freq=1, verbose=2, train_bs=None, eval_bs=None):
+        super(LoggerCallBack, self).__init__(log_freq, verbose)
+        self.train_bs = train_bs
+        self.eval_bs = eval_bs if eval_bs else train_bs
+
+    def on_train_batch_end(self, step, logs=None):
+        logs = logs or {}
+        logs['loss'] = [l / self.train_bs for l in logs['loss']]
+        super(LoggerCallBack, self).on_train_batch_end(step, logs)
+
+    def on_epoch_end(self, epoch, logs=None):
+        logs = logs or {}
+        logs['loss'] = [l / self.train_bs for l in logs['loss']]
+        super(LoggerCallBack, self).on_epoch_end(epoch, logs)
+
+    def on_eval_batch_end(self, step, logs=None):
+        logs = logs or {}
+        logs['loss'] = [l / self.eval_bs for l in logs['loss']]
+        super(LoggerCallBack, self).on_eval_batch_end(step, logs)
+
+    def on_eval_end(self, logs=None):
+        logs = logs or {}
+        logs['loss'] = [l / self.eval_bs for l in logs['loss']]
+        super(LoggerCallBack, self).on_eval_end(logs)
+
+
+def index2word(ids):
+    return [chr(int(k + 33)) for k in ids]
+
+
+def postprocess(seq, bos_idx=0, eos_idx=1):
+    if type(seq) is np.ndarray:
+        seq = seq.tolist()
+    eos_pos = len(seq) - 1
+    for i, idx in enumerate(seq):
+        if idx == eos_idx:
+            eos_pos = i
+            break
+    seq = [
+        idx for idx in seq[:eos_pos + 1] if idx != bos_idx and idx != eos_idx
+    ]
+    return seq
+
+
+class SeqBeamAccuracy(Metric):
+    def __init__(self, name=None, *args, **kwargs):
+        super(SeqBeamAccuracy, self).__init__(*args, **kwargs)
+        self._name = 'seq_acc'
+        self.reset()
+
+    def add_metric_op(self, output, label, mask, *args, **kwargs):
+        return output, label, mask
+
+    def update(self, preds, labels, masks, *args, **kwargs):
+        preds = preds[:, :, np.newaxis] if len(preds.shape) == 2 else preds
+        preds = np.transpose(preds, [0, 2, 1])
+        seq_len = np.sum(masks, -1)
+        acc = 0
+        for i in range(labels.shape[0]):
+            l = int(seq_len[i] - 1)
+            #ref = labels[i][: l - 1]
+            ref = np.array(postprocess(labels[i]))
+            pred = preds[i]
+            for idx, beam in enumerate(pred):
+                beam_pred = np.array(postprocess(beam))
+                if np.array_equal(beam_pred, ref):
+                    self.total += 1
+                    acc += 1
+                    break
+            self.count += 1
+        return float(acc) / labels.shape[0]
+
+    def reset(self):
+        self.total = 0.
+        self.count = 0.
+
+    def accumulate(self):
+        return float(self.total) / self.count
+
+    def name(self):
+        return self._name

examples/seq2seq/README.md

+运行本目录下的范例模型需要安装PaddlePaddle Fluid 1.7版。如果您的 PaddlePaddle 安装版本低于此要求，请按照[安装文档](https://www.paddlepaddle.org.cn/#quick-start)中的说明更新 PaddlePaddle 安装版本。
+
+# Sequence to Sequence (Seq2Seq)
+
+以下是本范例模型的简要目录结构及说明：
+
+```
+.
+├── README.md              # 文档，本文件
+├── args.py                # 训练、预测以及模型参数配置程序
+├── reader.py              # 数据读入程序
+├── download.py            # 数据下载程序
+├── train.py               # 训练主程序
+├── predict.py             # 预测主程序
+├── seq2seq_attn.py        # 带注意力机制的翻译模型程序
+└── seq2seq_base.py        # 无注意力机制的翻译模型程序
+```
+
+## 简介
+
+Sequence to Sequence (Seq2Seq)，使用编码器-解码器（Encoder-Decoder）结构，用编码器将源序列编码成vector，再用解码器将该vector解码为目标序列。Seq2Seq 广泛应用于机器翻译，自动对话机器人，文档摘要自动生成，图片描述自动生成等任务中。
+
+本目录包含Seq2Seq的一个经典样例：机器翻译，实现了一个base model（不带attention机制），一个带attention机制的翻译模型。Seq2Seq翻译模型，模拟了人类在进行翻译类任务时的行为：先解析源语言，理解其含义，再根据该含义来写出目标语言的语句。更多关于机器翻译的具体原理和数学表达式，我们推荐参考飞桨官网[机器翻译案例](https://www.paddlepaddle.org.cn/documentation/docs/zh/user_guides/nlp_case/machine_translation/README.cn.html)。
+
+## 模型概览
+
+本模型中，在编码器方面，我们采用了基于LSTM的多层的RNN encoder；在解码器方面，我们使用了带注意力（Attention）机制的RNN decoder，并同时提供了一个不带注意力机制的解码器实现作为对比。在预测时我们使用柱搜索（beam search）算法来生成翻译的目标语句。
+
+## 数据介绍
+
+本教程使用[IWSLT'15 English-Vietnamese data ](https://nlp.stanford.edu/projects/nmt/)数据集中的英语到越南语的数据作为训练语料，tst2012的数据作为开发集，tst2013的数据作为测试集
+
+### 数据获取
+
+```
+python download.py
+```
+
+## 模型训练
+
+执行以下命令即可训练带有注意力机制的Seq2Seq机器翻译模型：
+
+```sh
+export CUDA_VISIBLE_DEVICES=0
+
+python train.py \
+    --src_lang en --tar_lang vi \
+    --attention True \
+    --num_layers 2 \
+    --hidden_size 512 \
+    --src_vocab_size 17191 \
+    --tar_vocab_size 7709 \
+    --batch_size 128 \
+    --dropout 0.2 \
+    --init_scale  0.1 \
+    --max_grad_norm 5.0 \
+    --train_data_prefix data/en-vi/train \
+    --eval_data_prefix data/en-vi/tst2012 \
+    --test_data_prefix data/en-vi/tst2013 \
+    --vocab_prefix data/en-vi/vocab \
+    --use_gpu True \
+    --model_path ./attention_models
+```
+
+可以通过修改 `attention` 参数为False来训练不带注意力机制的Seq2Seq模型，各参数的具体说明请参阅 `args.py` 。训练程序会在每个epoch训练结束之后，save一次模型。
+
+默认使用动态图模式进行训练，可以通过设置 `eager_run` 参数为False来以静态图模式进行训练，如下：
+
+```sh
+export CUDA_VISIBLE_DEVICES=0
+
+python train.py \
+    --src_lang en --tar_lang vi \
+    --attention True \
+    --num_layers 2 \
+    --hidden_size 512 \
+    --src_vocab_size 17191 \
+    --tar_vocab_size 7709 \
+    --batch_size 128 \
+    --dropout 0.2 \
+    --init_scale  0.1 \
+    --max_grad_norm 5.0 \
+    --train_data_prefix data/en-vi/train \
+    --eval_data_prefix data/en-vi/tst2012 \
+    --test_data_prefix data/en-vi/tst2013 \
+    --vocab_prefix data/en-vi/vocab \
+    --use_gpu True \
+    --model_path ./attention_models \
+    --eager_run False
+```
+
+## 模型预测
+
+训练完成之后，可以使用保存的模型（由 `--reload_model` 指定）对test的数据集（由 `--infer_file` 指定）进行beam search解码，命令如下：
+
+```sh
+export CUDA_VISIBLE_DEVICES=0
+
+python infer.py \
+    --attention True \
+    --src_lang en --tar_lang vi \
+    --num_layers 2 \
+    --hidden_size 512 \
+    --src_vocab_size 17191 \
+    --tar_vocab_size 7709 \
+    --batch_size 128 \
+    --dropout 0.2 \
+    --init_scale  0.1 \
+    --max_grad_norm 5.0 \
+    --vocab_prefix data/en-vi/vocab \
+    --infer_file data/en-vi/tst2013.en \
+    --reload_model attention_models/10 \
+    --infer_output_file infer_output.txt \
+    --beam_size 10 \
+    --use_gpu True
+```
+
+各参数的具体说明请参阅 `args.py` ，注意预测时所用模型超参数需和训练时一致。和训练类似，预测时同样可以以静态图模式进行，如下：
+
+```sh
+export CUDA_VISIBLE_DEVICES=0
+
+python infer.py \
+    --attention True \
+    --src_lang en --tar_lang vi \
+    --num_layers 2 \
+    --hidden_size 512 \
+    --src_vocab_size 17191 \
+    --tar_vocab_size 7709 \
+    --batch_size 128 \
+    --dropout 0.2 \
+    --init_scale  0.1 \
+    --max_grad_norm 5.0 \
+    --vocab_prefix data/en-vi/vocab \
+    --infer_file data/en-vi/tst2013.en \
+    --reload_model attention_models/10 \
+    --infer_output_file infer_output.txt \
+    --beam_size 10 \
+    --use_gpu True \
+    --eager_run False  
+```
+
+## 效果评价
+
+使用 [*multi-bleu.perl*](https://github.com/moses-smt/mosesdecoder.git) 工具来评价模型预测的翻译质量，使用方法如下：
+
+```sh
+mosesdecoder/scripts/generic/multi-bleu.perl tst2013.vi < infer_output.txt
+```
+
+每个模型分别训练了10次，单次取第10个epoch保存的模型进行预测，取beam_size=10。效果如下（为了便于观察，对10次结果按照升序进行了排序）：
+
+```
+> no attention
+tst2012 BLEU:
+[10.75 10.85 10.9  10.94 10.97 11.01 11.01 11.04 11.13 11.4]
+tst2013 BLEU:
+[10.71 10.71 10.74 10.76 10.91 10.94 11.02 11.16 11.21 11.44]
+
+> with attention
+tst2012 BLEU:
+[21.14 22.34 22.54 22.65 22.71 22.71 23.08 23.15 23.3  23.4]
+tst2013 BLEU:
+[23.41 24.79 25.11 25.12 25.19 25.24 25.39 25.61 25.61 25.63]
+```

examples/seq2seq/args.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import argparse
+import distutils.util
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        "--train_data_prefix", type=str, help="file prefix for train data")
+    parser.add_argument(
+        "--eval_data_prefix", type=str, help="file prefix for eval data")
+    parser.add_argument(
+        "--test_data_prefix", type=str, help="file prefix for test data")
+    parser.add_argument(
+        "--vocab_prefix", type=str, help="file prefix for vocab")
+    parser.add_argument("--src_lang", type=str, help="source language suffix")
+    parser.add_argument("--tar_lang", type=str, help="target language suffix")
+
+    parser.add_argument(
+        "--attention",
+        type=eval,
+        default=False,
+        help="Whether use attention model")
+
+    parser.add_argument(
+        "--optimizer",
+        type=str,
+        default='adam',
+        help="optimizer to use, only supprt[sgd|adam]")
+
+    parser.add_argument(
+        "--learning_rate",
+        type=float,
+        default=0.001,
+        help="learning rate for optimizer")
+
+    parser.add_argument(
+        "--num_layers",
+        type=int,
+        default=1,
+        help="layers number of encoder and decoder")
+    parser.add_argument(
+        "--hidden_size",
+        type=int,
+        default=100,
+        help="hidden size of encoder and decoder")
+    parser.add_argument("--src_vocab_size", type=int, help="source vocab size")
+    parser.add_argument("--tar_vocab_size", type=int, help="target vocab size")
+
+    parser.add_argument(
+        "--batch_size", type=int, help="batch size of each step")
+
+    parser.add_argument(
+        "--max_epoch", type=int, default=12, help="max epoch for the training")
+
+    parser.add_argument(
+        "--max_len",
+        type=int,
+        default=50,
+        help="max length for source and target sentence")
+    parser.add_argument(
+        "--dropout", type=float, default=0.0, help="drop probability")
+    parser.add_argument(
+        "--init_scale",
+        type=float,
+        default=0.0,
+        help="init scale for parameter")
+    parser.add_argument(
+        "--max_grad_norm",
+        type=float,
+        default=5.0,
+        help="max grad norm for global norm clip")
+
+    parser.add_argument(
+        "--log_freq",
+        type=int,
+        default=100,
+        help="The frequency to print training logs")
+
+    parser.add_argument(
+        "--model_path",
+        type=str,
+        default='model',
+        help="model path for model to save")
+
+    parser.add_argument(
+        "--reload_model", type=str, help="reload model to inference")
+
+    parser.add_argument(
+        "--infer_file", type=str, help="file name for inference")
+    parser.add_argument(
+        "--infer_output_file",
+        type=str,
+        default='infer_output',
+        help="file name for inference output")
+    parser.add_argument(
+        "--beam_size", type=int, default=10, help="file name for inference")
+
+    parser.add_argument(
+        '--use_gpu',
+        type=eval,
+        default=False,
+        help='Whether using gpu [True|False]')
+
+    parser.add_argument(
+        '--eager_run', type=eval, default=False, help='Whether to use dygraph')
+
+    parser.add_argument(
+        "--enable_ce",
+        action='store_true',
+        help="The flag indicating whether to run the task "
+        "for continuous evaluation.")
+
+    parser.add_argument(
+        "--profile", action='store_true', help="Whether enable the profile.")
+    # NOTE: profiler args, used for benchmark
+    parser.add_argument(
+        "--profiler_path",
+        type=str,
+        default='./seq2seq.profile',
+        help="the profiler output file path. (used for benchmark)")
+    args = parser.parse_args()
+    return args

examples/seq2seq/download.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an 'AS IS' BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+'''
+Script for downloading training data.
+'''
+import os
+import urllib
+import sys
+
+if sys.version_info >= (3, 0):
+    import urllib.request
+import zipfile
+
+URLLIB = urllib
+if sys.version_info >= (3, 0):
+    URLLIB = urllib.request
+
+remote_path = 'https://nlp.stanford.edu/projects/nmt/data/iwslt15.en-vi'
+base_path = 'data'
+tar_path = os.path.join(base_path, 'en-vi')
+filenames = [
+    'train.en', 'train.vi', 'tst2012.en', 'tst2012.vi', 'tst2013.en',
+    'tst2013.vi', 'vocab.en', 'vocab.vi'
+]
+
+
+def main(arguments):
+    print("Downloading data......")
+
+    if not os.path.exists(tar_path):
+        if not os.path.exists(base_path):
+            os.mkdir(base_path)
+        os.mkdir(tar_path)
+
+    for filename in filenames:
+        url = remote_path + '/' + filename
+        tar_file = os.path.join(tar_path, filename)
+        URLLIB.urlretrieve(url, tar_file)
+    print("Downloaded sucess......")
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv[1:]))

examples/seq2seq/predict.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+import os
+import io
+import random
+from functools import partial
+
+import numpy as np
+import paddle.fluid as fluid
+from paddle.fluid.layers.utils import flatten
+from paddle.fluid.io import DataLoader
+
+from hapi.model import Input, set_device
+from args import parse_args
+from seq2seq_base import BaseInferModel
+from seq2seq_attn import AttentionInferModel
+from reader import Seq2SeqDataset, Seq2SeqBatchSampler, SortType, prepare_infer_input
+
+
+def post_process_seq(seq, bos_idx, eos_idx, output_bos=False,
+                     output_eos=False):
+    """
+    Post-process the decoded sequence.
+    """
+    eos_pos = len(seq) - 1
+    for i, idx in enumerate(seq):
+        if idx == eos_idx:
+            eos_pos = i
+            break
+    seq = [
+        idx for idx in seq[:eos_pos + 1]
+        if (output_bos or idx != bos_idx) and (output_eos or idx != eos_idx)
+    ]
+    return seq
+
+
+def do_predict(args):
+    device = set_device("gpu" if args.use_gpu else "cpu")
+    fluid.enable_dygraph(device) if args.eager_run else None
+
+    # define model
+    inputs = [
+        Input(
+            [None, None], "int64", name="src_word"),
+        Input(
+            [None], "int64", name="src_length"),
+    ]
+
+    # def dataloader
+    dataset = Seq2SeqDataset(
+        fpattern=args.infer_file,
+        src_vocab_fpath=args.vocab_prefix + "." + args.src_lang,
+        trg_vocab_fpath=args.vocab_prefix + "." + args.tar_lang,
+        token_delimiter=None,
+        start_mark="<s>",
+        end_mark="</s>",
+        unk_mark="<unk>")
+    trg_idx2word = Seq2SeqDataset.load_dict(
+        dict_path=args.vocab_prefix + "." + args.tar_lang, reverse=True)
+    (args.src_vocab_size, args.trg_vocab_size, bos_id, eos_id,
+     unk_id) = dataset.get_vocab_summary()
+    batch_sampler = Seq2SeqBatchSampler(
+        dataset=dataset, use_token_batch=False, batch_size=args.batch_size)
+    data_loader = DataLoader(
+        dataset=dataset,
+        batch_sampler=batch_sampler,
+        places=device,
+        feed_list=None
+        if fluid.in_dygraph_mode() else [x.forward() for x in inputs],
+        collate_fn=partial(
+            prepare_infer_input, bos_id=bos_id, eos_id=eos_id, pad_id=eos_id),
+        num_workers=0,
+        return_list=True)
+
+    model_maker = AttentionInferModel if args.attention else BaseInferModel
+    model = model_maker(
+        args.src_vocab_size,
+        args.tar_vocab_size,
+        args.hidden_size,
+        args.hidden_size,
+        args.num_layers,
+        args.dropout,
+        bos_id=bos_id,
+        eos_id=eos_id,
+        beam_size=args.beam_size,
+        max_out_len=256)
+
+    model.prepare(inputs=inputs)
+
+    # load the trained model
+    assert args.reload_model, (
+        "Please set reload_model to load the infer model.")
+    model.load(args.reload_model)
+
+    # TODO(guosheng): use model.predict when support variant length
+    with io.open(args.infer_output_file, 'w', encoding='utf-8') as f:
+        for data in data_loader():
+            finished_seq = model.test_batch(inputs=flatten(data))[0]
+            finished_seq = finished_seq[:, :, np.newaxis] if len(
+                finished_seq.shape) == 2 else finished_seq
+            finished_seq = np.transpose(finished_seq, [0, 2, 1])
+            for ins in finished_seq:
+                for beam_idx, beam in enumerate(ins):
+                    id_list = post_process_seq(beam, bos_id, eos_id)
+                    word_list = [trg_idx2word[id] for id in id_list]
+                    sequence = " ".join(word_list) + "\n"
+                    f.write(sequence)
+                    break
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    do_predict(args)

examples/seq2seq/reader.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import glob
+import six
+import os
+import io
+import itertools
+from functools import partial
+
+import numpy as np
+import paddle.fluid as fluid
+from paddle.fluid.dygraph.parallel import ParallelEnv
+from paddle.fluid.io import BatchSampler, DataLoader, Dataset
+
+
+def create_data_loader(args, device, for_train=True):
+    data_loaders = [None, None]
+    data_prefixes = [args.train_data_prefix, args.eval_data_prefix
+                     ] if args.eval_data_prefix else [args.train_data_prefix]
+    for i, data_prefix in enumerate(data_prefixes):
+        dataset = Seq2SeqDataset(
+            fpattern=data_prefix + "." + args.src_lang,
+            trg_fpattern=data_prefix + "." + args.tar_lang,
+            src_vocab_fpath=args.vocab_prefix + "." + args.src_lang,
+            trg_vocab_fpath=args.vocab_prefix + "." + args.tar_lang,
+            token_delimiter=None,
+            start_mark="<s>",
+            end_mark="</s>",
+            unk_mark="<unk>",
+            max_length=args.max_len if i == 0 else None,
+            truncate=True,
+            trg_add_bos_eos=True)
+        (args.src_vocab_size, args.tar_vocab_size, bos_id, eos_id,
+         unk_id) = dataset.get_vocab_summary()
+        batch_sampler = Seq2SeqBatchSampler(
+            dataset=dataset,
+            use_token_batch=False,
+            batch_size=args.batch_size,
+            pool_size=args.batch_size * 20,
+            sort_type=SortType.POOL,
+            shuffle=False if args.enable_ce else True,
+            distribute_mode=True if i == 0 else False)
+        data_loader = DataLoader(
+            dataset=dataset,
+            batch_sampler=batch_sampler,
+            places=device,
+            collate_fn=partial(
+                prepare_train_input,
+                bos_id=bos_id,
+                eos_id=eos_id,
+                pad_id=eos_id),
+            num_workers=0,
+            return_list=True)
+        data_loaders[i] = data_loader
+    return data_loaders
+
+
+def prepare_train_input(insts, bos_id, eos_id, pad_id):
+    src, src_length = pad_batch_data(
+        [inst[0] for inst in insts], pad_id=pad_id)
+    trg, trg_length = pad_batch_data(
+        [inst[1] for inst in insts], pad_id=pad_id)
+    trg_length = trg_length - 1
+    return src, src_length, trg[:, :-1], trg_length, trg[:, 1:, np.newaxis]
+
+
+def prepare_infer_input(insts, bos_id, eos_id, pad_id):
+    src, src_length = pad_batch_data(insts, pad_id=pad_id)
+    return src, src_length
+
+
+def pad_batch_data(insts, pad_id):
+    """
+    Pad the instances to the max sequence length in batch, and generate the
+    corresponding position data and attention bias.
+    """
+    inst_lens = np.array([len(inst) for inst in insts], dtype="int64")
+    max_len = np.max(inst_lens)
+    inst_data = np.array(
+        [inst + [pad_id] * (max_len - len(inst)) for inst in insts],
+        dtype="int64")
+    return inst_data, inst_lens
+
+
+class SortType(object):
+    GLOBAL = 'global'
+    POOL = 'pool'
+    NONE = "none"
+
+
+class Converter(object):
+    def __init__(self, vocab, beg, end, unk, delimiter, add_beg, add_end):
+        self._vocab = vocab
+        self._beg = beg
+        self._end = end
+        self._unk = unk
+        self._delimiter = delimiter
+        self._add_beg = add_beg
+        self._add_end = add_end
+
+    def __call__(self, sentence):
+        return ([self._beg] if self._add_beg else []) + [
+            self._vocab.get(w, self._unk)
+            for w in sentence.split(self._delimiter)
+        ] + ([self._end] if self._add_end else [])
+
+
+class ComposedConverter(object):
+    def __init__(self, converters):
+        self._converters = converters
+
+    def __call__(self, fields):
+        return [
+            converter(field)
+            for field, converter in zip(fields, self._converters)
+        ]
+
+
+class SentenceBatchCreator(object):
+    def __init__(self, batch_size):
+        self.batch = []
+        self._batch_size = batch_size
+
+    def append(self, info):
+        self.batch.append(info)
+        if len(self.batch) == self._batch_size:
+            tmp = self.batch
+            self.batch = []
+            return tmp
+
+
+class TokenBatchCreator(object):
+    def __init__(self, batch_size):
+        self.batch = []
+        self.max_len = -1
+        self._batch_size = batch_size
+
+    def append(self, info):
+        cur_len = info.max_len
+        max_len = max(self.max_len, cur_len)
+        if max_len * (len(self.batch) + 1) > self._batch_size:
+            result = self.batch
+            self.batch = [info]
+            self.max_len = cur_len
+            return result
+        else:
+            self.max_len = max_len
+            self.batch.append(info)
+
+
+class SampleInfo(object):
+    def __init__(self, i, lens):
+        self.i = i
+        self.lens = lens
+        self.max_len = lens[0]  # to be consitent with the original reader
+
+    def get_ranges(self, min_length=None, max_length=None, truncate=False):
+        ranges = []
+        # source
+        if (min_length is None or self.lens[0] >= min_length) and (
+                max_length is None or self.lens[0] <= max_length or truncate):
+            end = max_length if truncate and max_length else self.lens[0]
+            ranges.append([0, end])
+        # target
+        if len(self.lens) == 2:
+            if (min_length is None or self.lens[1] >= min_length) and (
+                    max_length is None or self.lens[1] <= max_length + 2 or
+                    truncate):
+                end = max_length + 2 if truncate and max_length else self.lens[
+                    1]
+                ranges.append([0, end])
+        return ranges if len(ranges) == len(self.lens) else None
+
+
+class MinMaxFilter(object):
+    def __init__(self, max_len, min_len, underlying_creator):
+        self._min_len = min_len
+        self._max_len = max_len
+        self._creator = underlying_creator
+
+    def append(self, info):
+        if (self._min_len is None or info.min_len >= self._min_len) and (
+                self._max_len is None or info.max_len <= self._max_len):
+            return self._creator.append(info)
+
+    @property
+    def batch(self):
+        return self._creator.batch
+
+
+class Seq2SeqDataset(Dataset):
+    def __init__(self,
+                 src_vocab_fpath,
+                 trg_vocab_fpath,
+                 fpattern,
+                 field_delimiter="\t",
+                 token_delimiter=" ",
+                 start_mark="<s>",
+                 end_mark="<e>",
+                 unk_mark="<unk>",
+                 trg_fpattern=None,
+                 trg_add_bos_eos=False,
+                 byte_data=False,
+                 min_length=None,
+                 max_length=None,
+                 truncate=False):
+        if byte_data:
+            # The WMT16 bpe data used here seems including bytes can not be
+            # decoded by utf8. Thus convert str to bytes, and use byte data
+            field_delimiter = field_delimiter.encode("utf8")
+            token_delimiter = token_delimiter.encode("utf8")
+            start_mark = start_mark.encode("utf8")
+            end_mark = end_mark.encode("utf8")
+            unk_mark = unk_mark.encode("utf8")
+        self._byte_data = byte_data
+        self._src_vocab = self.load_dict(src_vocab_fpath, byte_data=byte_data)
+        self._trg_vocab = self.load_dict(trg_vocab_fpath, byte_data=byte_data)
+        self._bos_idx = self._src_vocab[start_mark]
+        self._eos_idx = self._src_vocab[end_mark]
+        self._unk_idx = self._src_vocab[unk_mark]
+        self._field_delimiter = field_delimiter
+        self._token_delimiter = token_delimiter
+        self._min_length = min_length
+        self._max_length = max_length
+        self._truncate = truncate
+        self._trg_add_bos_eos = trg_add_bos_eos
+        self.load_src_trg_ids(fpattern, trg_fpattern)
+
+    def load_src_trg_ids(self, fpattern, trg_fpattern=None):
+        src_converter = Converter(
+            vocab=self._src_vocab,
+            beg=self._bos_idx,
+            end=self._eos_idx,
+            unk=self._unk_idx,
+            delimiter=self._token_delimiter,
+            add_beg=False,
+            add_end=False)
+
+        trg_converter = Converter(
+            vocab=self._trg_vocab,
+            beg=self._bos_idx,
+            end=self._eos_idx,
+            unk=self._unk_idx,
+            delimiter=self._token_delimiter,
+            add_beg=True if self._trg_add_bos_eos else False,
+            add_end=True if self._trg_add_bos_eos else False)
+
+        converters = ComposedConverter([src_converter, trg_converter])
+
+        self._src_seq_ids = []
+        self._trg_seq_ids = []
+        self._sample_infos = []
+
+        slots = [self._src_seq_ids, self._trg_seq_ids]
+        for i, line in enumerate(self._load_lines(fpattern, trg_fpattern)):
+            fields = converters(line)
+            lens = [len(field) for field in fields]
+            sample = SampleInfo(i, lens)
+            field_ranges = sample.get_ranges(self._min_length,
+                                             self._max_length, self._truncate)
+            if field_ranges:
+                for field, field_range, slot in zip(fields, field_ranges,
+                                                    slots):
+                    slot.append(field[field_range[0]:field_range[1]])
+                self._sample_infos.append(sample)
+
+    def _load_lines(self, fpattern, trg_fpattern=None):
+        fpaths = glob.glob(fpattern)
+        fpaths = sorted(fpaths)  # TODO: Add custum sort
+        assert len(fpaths) > 0, "no matching file to the provided data path"
+
+        (f_mode, f_encoding,
+         endl) = ("rb", None, b"\n") if self._byte_data else ("r", "utf8",
+                                                              "\n")
+        if trg_fpattern is None:
+            for fpath in fpaths:
+                with io.open(fpath, f_mode, encoding=f_encoding) as f:
+                    for line in f:
+                        fields = line.strip(endl).split(self._field_delimiter)
+                        yield fields
+        else:
+            # separated source and target language data files
+            # assume we can get aligned data by sort the two language files
+            # TODO: Need more rigorous check
+            trg_fpaths = glob.glob(trg_fpattern)
+            trg_fpaths = sorted(trg_fpaths)
+            assert len(fpaths) == len(
+                trg_fpaths
+            ), "the number of source language data files must equal \
+                with that of source language"
+
+            for fpath, trg_fpath in zip(fpaths, trg_fpaths):
+                with io.open(fpath, f_mode, encoding=f_encoding) as f:
+                    with io.open(
+                            trg_fpath, f_mode, encoding=f_encoding) as trg_f:
+                        for line in zip(f, trg_f):
+                            fields = [field.strip(endl) for field in line]
+                            yield fields
+
+    @staticmethod
+    def load_dict(dict_path, reverse=False, byte_data=False):
+        word_dict = {}
+        (f_mode, f_encoding,
+         endl) = ("rb", None, b"\n") if byte_data else ("r", "utf8", "\n")
+        with io.open(dict_path, f_mode, encoding=f_encoding) as fdict:
+            for idx, line in enumerate(fdict):
+                if reverse:
+                    word_dict[idx] = line.strip(endl)
+                else:
+                    word_dict[line.strip(endl)] = idx
+        return word_dict
+
+    def get_vocab_summary(self):
+        return len(self._src_vocab), len(
+            self._trg_vocab), self._bos_idx, self._eos_idx, self._unk_idx
+
+    def __getitem__(self, idx):
+        return (self._src_seq_ids[idx], self._trg_seq_ids[idx]
+                ) if self._trg_seq_ids else self._src_seq_ids[idx]
+
+    def __len__(self):
+        return len(self._sample_infos)
+
+
+class Seq2SeqBatchSampler(BatchSampler):
+    def __init__(self,
+                 dataset,
+                 batch_size,
+                 pool_size=10000,
+                 sort_type=SortType.NONE,
+                 min_length=None,
+                 max_length=None,
+                 shuffle=False,
+                 shuffle_batch=False,
+                 use_token_batch=False,
+                 clip_last_batch=False,
+                 distribute_mode=True,
+                 seed=0):
+        for arg, value in locals().items():
+            if arg != "self":
+                setattr(self, "_" + arg, value)
+        self._random = np.random
+        self._random.seed(seed)
+        # for multi-devices
+        self._distribute_mode = distribute_mode
+        self._nranks = ParallelEnv().nranks
+        self._local_rank = ParallelEnv().local_rank
+        self._device_id = ParallelEnv().dev_id
+
+    def __iter__(self):
+        # global sort or global shuffle
+        if self._sort_type == SortType.GLOBAL:
+            infos = sorted(
+                self._dataset._sample_infos, key=lambda x: x.max_len)
+        else:
+            if self._shuffle:
+                infos = self._dataset._sample_infos
+                self._random.shuffle(infos)
+            else:
+                infos = self._dataset._sample_infos
+
+            if self._sort_type == SortType.POOL:
+                reverse = True
+                for i in range(0, len(infos), self._pool_size):
+                    # to avoid placing short next to long sentences
+                    reverse = False  # not reverse
+                    infos[i:i + self._pool_size] = sorted(
+                        infos[i:i + self._pool_size],
+                        key=lambda x: x.max_len,
+                        reverse=reverse)
+
+        batches = []
+        batch_creator = TokenBatchCreator(
+            self.
+            _batch_size) if self._use_token_batch else SentenceBatchCreator(
+                self._batch_size * self._nranks)
+        batch_creator = MinMaxFilter(self._max_length, self._min_length,
+                                     batch_creator)
+
+        for info in infos:
+            batch = batch_creator.append(info)
+            if batch is not None:
+                batches.append(batch)
+
+        if not self._clip_last_batch and len(batch_creator.batch) != 0:
+            batches.append(batch_creator.batch)
+
+        if self._shuffle_batch:
+            self._random.shuffle(batches)
+
+        if not self._use_token_batch:
+            # when producing batches according to sequence number, to confirm
+            # neighbor batches which would be feed and run parallel have similar
+            # length (thus similar computational cost) after shuffle, we as take
+            # them as a whole when shuffling and split here
+            batches = [[
+                batch[self._batch_size * i:self._batch_size * (i + 1)]
+                for i in range(self._nranks)
+            ] for batch in batches]
+            batches = list(itertools.chain.from_iterable(batches))
+
+        # for multi-device
+        for batch_id, batch in enumerate(batches):
+            if not self._distribute_mode or (
+                    batch_id % self._nranks == self._local_rank):
+                batch_indices = [info.i for info in batch]
+                yield batch_indices
+        if self._distribute_mode and len(batches) % self._nranks != 0:
+            if self._local_rank >= len(batches) % self._nranks:
+                # use previous data to pad
+                yield batch_indices
+
+    def __len__(self):
+        if not self._use_token_batch:
+            batch_number = (
+                len(self._dataset) + self._batch_size * self._nranks - 1) // (
+                    self._batch_size * self._nranks)
+        else:
+            # TODO(guosheng): fix the uncertain length
+            batch_number = 1
+        return batch_number

examples/seq2seq/seq2seq_attn.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import paddle.fluid as fluid
+import paddle.fluid.layers as layers
+from paddle.fluid import ParamAttr
+from paddle.fluid.initializer import UniformInitializer
+from paddle.fluid.dygraph import Embedding, Linear, Layer
+from paddle.fluid.layers import BeamSearchDecoder
+
+from hapi.model import Model, Loss
+from hapi.text import DynamicDecode, RNN, BasicLSTMCell, RNNCell
+
+from seq2seq_base import Encoder
+
+
+class AttentionLayer(Layer):
+    def __init__(self, hidden_size, bias=False, init_scale=0.1):
+        super(AttentionLayer, self).__init__()
+        self.input_proj = Linear(
+            hidden_size,
+            hidden_size,
+            param_attr=ParamAttr(initializer=UniformInitializer(
+                low=-init_scale, high=init_scale)),
+            bias_attr=bias)
+        self.output_proj = Linear(
+            hidden_size + hidden_size,
+            hidden_size,
+            param_attr=ParamAttr(initializer=UniformInitializer(
+                low=-init_scale, high=init_scale)),
+            bias_attr=bias)
+
+    def forward(self, hidden, encoder_output, encoder_padding_mask):
+        # query = self.input_proj(hidden)
+        encoder_output = self.input_proj(encoder_output)
+        attn_scores = layers.matmul(
+            layers.unsqueeze(hidden, [1]), encoder_output, transpose_y=True)
+        if encoder_padding_mask is not None:
+            attn_scores = layers.elementwise_add(attn_scores,
+                                                 encoder_padding_mask)
+        attn_scores = layers.softmax(attn_scores)
+        attn_out = layers.squeeze(
+            layers.matmul(attn_scores, encoder_output), [1])
+        attn_out = layers.concat([attn_out, hidden], 1)
+        attn_out = self.output_proj(attn_out)
+        return attn_out
+
+
+class DecoderCell(RNNCell):
+    def __init__(self,
+                 num_layers,
+                 input_size,
+                 hidden_size,
+                 dropout_prob=0.,
+                 init_scale=0.1):
+        super(DecoderCell, self).__init__()
+        self.dropout_prob = dropout_prob
+        # use add_sublayer to add multi-layers
+        self.lstm_cells = []
+        for i in range(num_layers):
+            self.lstm_cells.append(
+                self.add_sublayer(
+                    "lstm_%d" % i,
+                    BasicLSTMCell(
+                        input_size=input_size + hidden_size
+                        if i == 0 else hidden_size,
+                        hidden_size=hidden_size,
+                        param_attr=ParamAttr(initializer=UniformInitializer(
+                            low=-init_scale, high=init_scale)))))
+        self.attention_layer = AttentionLayer(hidden_size)
+
+    def forward(self,
+                step_input,
+                states,
+                encoder_output,
+                encoder_padding_mask=None):
+        lstm_states, input_feed = states
+        new_lstm_states = []
+        step_input = layers.concat([step_input, input_feed], 1)
+        for i, lstm_cell in enumerate(self.lstm_cells):
+            out, new_lstm_state = lstm_cell(step_input, lstm_states[i])
+            step_input = layers.dropout(
+                out,
+                self.dropout_prob,
+                dropout_implementation='upscale_in_train'
+            ) if self.dropout_prob > 0 else out
+            new_lstm_states.append(new_lstm_state)
+        out = self.attention_layer(step_input, encoder_output,
+                                   encoder_padding_mask)
+        return out, [new_lstm_states, out]
+
+
+class Decoder(Layer):
+    def __init__(self,
+                 vocab_size,
+                 embed_dim,
+                 hidden_size,
+                 num_layers,
+                 dropout_prob=0.,
+                 init_scale=0.1):
+        super(Decoder, self).__init__()
+        self.embedder = Embedding(
+            size=[vocab_size, embed_dim],
+            param_attr=ParamAttr(initializer=UniformInitializer(
+                low=-init_scale, high=init_scale)))
+        self.lstm_attention = RNN(DecoderCell(
+            num_layers, embed_dim, hidden_size, dropout_prob, init_scale),
+                                  is_reverse=False,
+                                  time_major=False)
+        self.output_layer = Linear(
+            hidden_size,
+            vocab_size,
+            param_attr=ParamAttr(initializer=UniformInitializer(
+                low=-init_scale, high=init_scale)),
+            bias_attr=False)
+
+    def forward(self, target, decoder_initial_states, encoder_output,
+                encoder_padding_mask):
+        inputs = self.embedder(target)
+        decoder_output, _ = self.lstm_attention(
+            inputs,
+            initial_states=decoder_initial_states,
+            encoder_output=encoder_output,
+            encoder_padding_mask=encoder_padding_mask)
+        predict = self.output_layer(decoder_output)
+        return predict
+
+
+class AttentionModel(Model):
+    def __init__(self,
+                 src_vocab_size,
+                 trg_vocab_size,
+                 embed_dim,
+                 hidden_size,
+                 num_layers,
+                 dropout_prob=0.,
+                 init_scale=0.1):
+        super(AttentionModel, self).__init__()
+        self.hidden_size = hidden_size
+        self.encoder = Encoder(src_vocab_size, embed_dim, hidden_size,
+                               num_layers, dropout_prob, init_scale)
+        self.decoder = Decoder(trg_vocab_size, embed_dim, hidden_size,
+                               num_layers, dropout_prob, init_scale)
+
+    def forward(self, src, src_length, trg):
+        # encoder
+        encoder_output, encoder_final_state = self.encoder(src, src_length)
+
+        # decoder initial states: use input_feed and the structure is
+        # [[h,c] * num_layers, input_feed], consistent with DecoderCell.states
+        decoder_initial_states = [
+            encoder_final_state,
+            self.decoder.lstm_attention.cell.get_initial_states(
+                batch_ref=encoder_output, shape=[self.hidden_size])
+        ]
+        # attention mask to avoid paying attention on padddings
+        src_mask = layers.sequence_mask(
+            src_length,
+            maxlen=layers.shape(src)[1],
+            dtype=encoder_output.dtype)
+        encoder_padding_mask = (src_mask - 1.0) * 1e9
+        encoder_padding_mask = layers.unsqueeze(encoder_padding_mask, [1])
+
+        # decoder with attentioon
+        predict = self.decoder(trg, decoder_initial_states, encoder_output,
+                               encoder_padding_mask)
+        return predict
+
+
+class AttentionInferModel(AttentionModel):
+    def __init__(self,
+                 src_vocab_size,
+                 trg_vocab_size,
+                 embed_dim,
+                 hidden_size,
+                 num_layers,
+                 dropout_prob=0.,
+                 bos_id=0,
+                 eos_id=1,
+                 beam_size=4,
+                 max_out_len=256):
+        args = dict(locals())
+        args.pop("self")
+        args.pop("__class__", None)  # py3
+        self.bos_id = args.pop("bos_id")
+        self.eos_id = args.pop("eos_id")
+        self.beam_size = args.pop("beam_size")
+        self.max_out_len = args.pop("max_out_len")
+        super(AttentionInferModel, self).__init__(**args)
+        # dynamic decoder for inference
+        decoder = BeamSearchDecoder(
+            self.decoder.lstm_attention.cell,
+            start_token=bos_id,
+            end_token=eos_id,
+            beam_size=beam_size,
+            embedding_fn=self.decoder.embedder,
+            output_fn=self.decoder.output_layer)
+        self.beam_search_decoder = DynamicDecode(
+            decoder, max_step_num=max_out_len, is_test=True)
+
+    def forward(self, src, src_length):
+        # encoding
+        encoder_output, encoder_final_state = self.encoder(src, src_length)
+
+        # decoder initial states
+        decoder_initial_states = [
+            encoder_final_state,
+            self.decoder.lstm_attention.cell.get_initial_states(
+                batch_ref=encoder_output, shape=[self.hidden_size])
+        ]
+        # attention mask to avoid paying attention on padddings
+        src_mask = layers.sequence_mask(
+            src_length,
+            maxlen=layers.shape(src)[1],
+            dtype=encoder_output.dtype)
+        encoder_padding_mask = (src_mask - 1.0) * 1e9
+        encoder_padding_mask = layers.unsqueeze(encoder_padding_mask, [1])
+
+        # Tile the batch dimension with beam_size
+        encoder_output = BeamSearchDecoder.tile_beam_merge_with_batch(
+            encoder_output, self.beam_size)
+        encoder_padding_mask = BeamSearchDecoder.tile_beam_merge_with_batch(
+            encoder_padding_mask, self.beam_size)
+
+        # dynamic decoding with beam search
+        rs, _ = self.beam_search_decoder(
+            inits=decoder_initial_states,
+            encoder_output=encoder_output,
+            encoder_padding_mask=encoder_padding_mask)
+        return rs

examples/seq2seq/seq2seq_base.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import paddle.fluid as fluid
+import paddle.fluid.layers as layers
+from paddle.fluid import ParamAttr
+from paddle.fluid.initializer import UniformInitializer
+from paddle.fluid.dygraph import Embedding, Linear, Layer
+from paddle.fluid.layers import BeamSearchDecoder
+
+from hapi.model import Model, Loss
+from hapi.text import DynamicDecode, RNN, BasicLSTMCell, RNNCell
+
+
+class CrossEntropyCriterion(Loss):
+    def __init__(self):
+        super(CrossEntropyCriterion, self).__init__()
+
+    def forward(self, outputs, labels):
+        predict, (trg_length, label) = outputs[0], labels
+        # for target padding mask
+        mask = layers.sequence_mask(
+            trg_length, maxlen=layers.shape(predict)[1], dtype=predict.dtype)
+
+        cost = layers.softmax_with_cross_entropy(
+            logits=predict, label=label, soft_label=False)
+        masked_cost = layers.elementwise_mul(cost, mask, axis=0)
+        batch_mean_cost = layers.reduce_mean(masked_cost, dim=[0])
+        seq_cost = layers.reduce_sum(batch_mean_cost)
+        return seq_cost
+
+
+class EncoderCell(RNNCell):
+    def __init__(self,
+                 num_layers,
+                 input_size,
+                 hidden_size,
+                 dropout_prob=0.,
+                 init_scale=0.1):
+        super(EncoderCell, self).__init__()
+        self.dropout_prob = dropout_prob
+        # use add_sublayer to add multi-layers
+        self.lstm_cells = []
+        for i in range(num_layers):
+            self.lstm_cells.append(
+                self.add_sublayer(
+                    "lstm_%d" % i,
+                    BasicLSTMCell(
+                        input_size=input_size if i == 0 else hidden_size,
+                        hidden_size=hidden_size,
+                        param_attr=ParamAttr(initializer=UniformInitializer(
+                            low=-init_scale, high=init_scale)))))
+
+    def forward(self, step_input, states):
+        new_states = []
+        for i, lstm_cell in enumerate(self.lstm_cells):
+            out, new_state = lstm_cell(step_input, states[i])
+            step_input = layers.dropout(
+                out,
+                self.dropout_prob,
+                dropout_implementation='upscale_in_train'
+            ) if self.dropout_prob > 0 else out
+            new_states.append(new_state)
+        return step_input, new_states
+
+    @property
+    def state_shape(self):
+        return [cell.state_shape for cell in self.lstm_cells]
+
+
+class Encoder(Layer):
+    def __init__(self,
+                 vocab_size,
+                 embed_dim,
+                 hidden_size,
+                 num_layers,
+                 dropout_prob=0.,
+                 init_scale=0.1):
+        super(Encoder, self).__init__()
+        self.embedder = Embedding(
+            size=[vocab_size, embed_dim],
+            param_attr=ParamAttr(initializer=UniformInitializer(
+                low=-init_scale, high=init_scale)))
+        self.stack_lstm = RNN(EncoderCell(num_layers, embed_dim, hidden_size,
+                                          dropout_prob, init_scale),
+                              is_reverse=False,
+                              time_major=False)
+
+    def forward(self, sequence, sequence_length):
+        inputs = self.embedder(sequence)
+        encoder_output, encoder_state = self.stack_lstm(
+            inputs, sequence_length=sequence_length)
+        return encoder_output, encoder_state
+
+
+DecoderCell = EncoderCell
+
+
+class Decoder(Layer):
+    def __init__(self,
+                 vocab_size,
+                 embed_dim,
+                 hidden_size,
+                 num_layers,
+                 dropout_prob=0.,
+                 init_scale=0.1):
+        super(Decoder, self).__init__()
+        self.embedder = Embedding(
+            size=[vocab_size, embed_dim],
+            param_attr=ParamAttr(initializer=UniformInitializer(
+                low=-init_scale, high=init_scale)))
+        self.stack_lstm = RNN(DecoderCell(num_layers, embed_dim, hidden_size,
+                                          dropout_prob, init_scale),
+                              is_reverse=False,
+                              time_major=False)
+        self.output_layer = Linear(
+            hidden_size,
+            vocab_size,
+            param_attr=ParamAttr(initializer=UniformInitializer(
+                low=-init_scale, high=init_scale)),
+            bias_attr=False)
+
+    def forward(self, target, decoder_initial_states):
+        inputs = self.embedder(target)
+        decoder_output, _ = self.stack_lstm(
+            inputs, initial_states=decoder_initial_states)
+        predict = self.output_layer(decoder_output)
+        return predict
+
+
+class BaseModel(Model):
+    def __init__(self,
+                 src_vocab_size,
+                 trg_vocab_size,
+                 embed_dim,
+                 hidden_size,
+                 num_layers,
+                 dropout_prob=0.,
+                 init_scale=0.1):
+        super(BaseModel, self).__init__()
+        self.hidden_size = hidden_size
+        self.encoder = Encoder(src_vocab_size, embed_dim, hidden_size,
+                               num_layers, dropout_prob, init_scale)
+        self.decoder = Decoder(trg_vocab_size, embed_dim, hidden_size,
+                               num_layers, dropout_prob, init_scale)
+
+    def forward(self, src, src_length, trg):
+        # encoder
+        encoder_output, encoder_final_states = self.encoder(src, src_length)
+
+        # decoder
+        predict = self.decoder(trg, encoder_final_states)
+        return predict
+
+
+class BaseInferModel(BaseModel):
+    def __init__(self,
+                 src_vocab_size,
+                 trg_vocab_size,
+                 embed_dim,
+                 hidden_size,
+                 num_layers,
+                 dropout_prob=0.,
+                 bos_id=0,
+                 eos_id=1,
+                 beam_size=4,
+                 max_out_len=256):
+        args = dict(locals())
+        args.pop("self")
+        args.pop("__class__", None)  # py3
+        self.bos_id = args.pop("bos_id")
+        self.eos_id = args.pop("eos_id")
+        self.beam_size = args.pop("beam_size")
+        self.max_out_len = args.pop("max_out_len")
+        super(BaseInferModel, self).__init__(**args)
+        # dynamic decoder for inference
+        decoder = BeamSearchDecoder(
+            self.decoder.stack_lstm.cell,
+            start_token=bos_id,
+            end_token=eos_id,
+            beam_size=beam_size,
+            embedding_fn=self.decoder.embedder,
+            output_fn=self.decoder.output_layer)
+        self.beam_search_decoder = DynamicDecode(
+            decoder, max_step_num=max_out_len, is_test=True)
+
+    def forward(self, src, src_length):
+        # encoding
+        encoder_output, encoder_final_states = self.encoder(src, src_length)
+        # dynamic decoding with beam search
+        rs, _ = self.beam_search_decoder(inits=encoder_final_states)
+        return rs

examples/seq2seq/train.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+import os
+import random
+from functools import partial
+
+import numpy as np
+import paddle.fluid as fluid
+from paddle.fluid.io import DataLoader
+
+from hapi.model import Input, set_device
+from args import parse_args
+from seq2seq_base import BaseModel, CrossEntropyCriterion
+from seq2seq_attn import AttentionModel
+from reader import create_data_loader
+from utility import PPL, TrainCallback
+
+
+def do_train(args):
+    device = set_device("gpu" if args.use_gpu else "cpu")
+    fluid.enable_dygraph(device) if args.eager_run else None
+
+    if args.enable_ce:
+        fluid.default_main_program().random_seed = 102
+        fluid.default_startup_program().random_seed = 102
+
+    # define model
+    inputs = [
+        Input(
+            [None, None], "int64", name="src_word"),
+        Input(
+            [None], "int64", name="src_length"),
+        Input(
+            [None, None], "int64", name="trg_word"),
+    ]
+    labels = [
+        Input(
+            [None], "int64", name="trg_length"),
+        Input(
+            [None, None, 1], "int64", name="label"),
+    ]
+
+    # def dataloader
+    train_loader, eval_loader = create_data_loader(args, device)
+
+    model_maker = AttentionModel if args.attention else BaseModel
+    model = model_maker(args.src_vocab_size, args.tar_vocab_size,
+                        args.hidden_size, args.hidden_size, args.num_layers,
+                        args.dropout)
+    grad_clip = fluid.clip.GradientClipByGlobalNorm(
+        clip_norm=args.max_grad_norm)
+    optimizer = fluid.optimizer.Adam(
+        learning_rate=args.learning_rate,
+        parameter_list=model.parameters(),
+        grad_clip=grad_clip)
+
+    ppl_metric = PPL(reset_freq=100)  # ppl for every 100 batches
+    model.prepare(
+        optimizer,
+        CrossEntropyCriterion(),
+        ppl_metric,
+        inputs=inputs,
+        labels=labels)
+    model.fit(train_data=train_loader,
+              eval_data=eval_loader,
+              epochs=args.max_epoch,
+              eval_freq=1,
+              save_freq=1,
+              save_dir=args.model_path,
+              callbacks=[TrainCallback(ppl_metric, args.log_freq)])
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    do_train(args)

examples/seq2seq/utility.py

+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import math
+
+import paddle.fluid as fluid
+
+from hapi.metrics import Metric
+from hapi.callbacks import ProgBarLogger
+
+
+class TrainCallback(ProgBarLogger):
+    def __init__(self, ppl, log_freq, verbose=2):
+        super(TrainCallback, self).__init__(log_freq, verbose)
+        self.ppl = ppl
+
+    def on_train_begin(self, logs=None):
+        super(TrainCallback, self).on_train_begin(logs)
+        self.train_metrics = ["ppl"]  # remove loss to not print it
+
+    def on_epoch_begin(self, epoch=None, logs=None):
+        super(TrainCallback, self).on_epoch_begin(epoch, logs)
+        self.ppl.reset()
+
+    def on_train_batch_end(self, step, logs=None):
+        logs["ppl"] = self.ppl.cal_acc_ppl(logs["loss"][0], logs["batch_size"])
+        if step > 0 and step % self.ppl.reset_freq == 0:
+            self.ppl.reset()
+        super(TrainCallback, self).on_train_batch_end(step, logs)
+
+    def on_eval_begin(self, logs=None):
+        super(TrainCallback, self).on_eval_begin(logs)
+        self.eval_metrics = ["ppl"]
+        self.ppl.reset()
+
+    def on_eval_batch_end(self, step, logs=None):
+        logs["ppl"] = self.ppl.cal_acc_ppl(logs["loss"][0], logs["batch_size"])
+        super(TrainCallback, self).on_eval_batch_end(step, logs)
+
+
+class PPL(Metric):
+    def __init__(self, reset_freq=100, name=None):
+        super(PPL, self).__init__()
+        self._name = name or "ppl"
+        self.reset_freq = reset_freq
+        self.reset()
+
+    def add_metric_op(self, pred, seq_length, label):
+        word_num = fluid.layers.reduce_sum(seq_length)
+        return word_num
+
+    def update(self, word_num):
+        self.word_count += word_num
+        return word_num
+
+    def reset(self):
+        self.total_loss = 0
+        self.word_count = 0
+
+    def accumulate(self):
+        return self.word_count
+
+    def name(self):
+        return self._name
+
+    def cal_acc_ppl(self, batch_loss, batch_size):
+        self.total_loss += batch_loss * batch_size
+        ppl = math.exp(self.total_loss / self.word_count)
+        return ppl
\ No newline at end of file

examples/sequence_tagging/README.md

@@ -6,7 +6,7 @@ Sequence Tagging，是一个序列标注模型，模型可用于实现，分词
 
 |模型|Precision|Recall|F1-score|
 |:-:|:-:|:-:|:-:|
-|Lexical Analysis|88.26%|89.20%|88.73%|
+|Lexical Analysis|89.57%|89.96%|89.76%|
 
 ## 2. 快速开始
 
@@ -22,7 +22,7 @@ Sequence Tagging，是一个序列标注模型，模型可用于实现，分词
 克隆工具集代码库到本地
 ```bash
  git clone https://github.com/PaddlePaddle/hapi.git
- cd hapi/sequence_tagging
+ cd hapi/examples/sequence_tagging
 ```
 
 #### 3. 环境依赖
@@ -70,7 +70,7 @@ python -u train.py \
           --dynamic False
 
 # --device: 使用gpu设备还是cpu设备
-# --dynamic： 是否使用动态图模式进行训练，如果使用静态图训练，设置为True, 动态图设置为False
+# --dynamic： 是否使用动态图模式进行训练，如果使用静态图训练，设置为False, 动态图设置为True
 ```
 
 GPU上多卡训练
@@ -84,7 +84,7 @@ python -m paddle.distributed.launch --selected_gpus=0,1,2,3  train.py \
           --dynamic False
 
 # --device: 使用gpu设备还是cpu设备
-# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为True, 动态图设置为False
+# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为False, 动态图设置为True
 ```
 
 CPU上训练
@@ -95,7 +95,7 @@ python -u train.py \
           --dynamic False
 
 # --device: 使用gpu设备还是cpu设备
-# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为True, 动态图设置为False
+# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为False, 动态图设置为True
 ```
 
 ### 模型预测
@@ -105,15 +105,13 @@ python -u train.py \
 python predict.py \
       --init_from_checkpoint  model_baseline/params \
       --output_file predict.result  \
-      --mode predict \
       --device cpu  \
       --dynamic False
 
 # --init_from_checkpoint: 初始化模型
 # --output_file: 预测结果文件
 # --device: 使用gpu还是cpu设备
-# --mode: 开启模式, 设置为train时，进行训练，设置为predict时进行预测
-# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为True, 动态图设置为False
+# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为False, 动态图设置为True
 ```
 
 ### 模型评估
@@ -123,14 +121,12 @@ python predict.py \
 # baseline model
 python eval.py \
         --init_from_checkpoint  ./model_baseline/params \
-        --mode predict \
         --device cpu  \
         --dynamic False
 
 # --init_from_checkpoint: 初始化模型
 # --device: 使用gpu还是cpu设备
-# --mode: 开启模式, 设置为train时，进行训练，设置为predict时进行预测
-# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为True, 动态图设置为False
+# --dynamic: 是否使用动态图模式进行训练，如果使用静态图训练，设置为False, 动态图设置为True
 ```
 
 
@@ -168,7 +164,7 @@ Overall Architecture of GRU-CRF-MODEL
 训练使用的数据可以由用户根据实际的应用场景，自己组织数据。除了第一行是 `text_a\tlabel` 固定的开头，后面的每行数据都是由两列组成，以制表符分隔，第一列是 utf-8 编码的中文文本，以 `\002` 分割，第二列是对应每个字的标注，以 `\002` 分隔。我们采用 IOB2 标注体系，即以 X-B 作为类型为 X 的词的开始，以 X-I 作为类型为 X 的词的持续，以 O 表示不关注的字（实际上，在词性、专名联合标注中，不存在 O ）。示例如下：
 
 ```text
-除\002了\002他\002续\002任\002十\002二\002届\002政\002协\002委\002员\002,\002马\002化\002腾\002,\002雷\002军\002,\002李\002彦\002宏\002也\002被\002推\002选\002为\002新\002一\002届\002全\002国\002人\002大\002代\002表\002或\002全\002国\002政\002协\002委\002员	p-B\002p-I\002r-B\002v-B\002v-I\002m-B\002m-I\002m-I\002ORG-B\002ORG-I\002n-B\002n-I\002w-B\002PER-B\002PER-I\002PER-I\002w-B\002PER-B\002PER-I\002w-B\002PER-B\002PER-I\002PER-I\002d-B\002p-B\002v-B\002v-I\002v-B\002a-B\002m-B\002m-I\002ORG-B\002ORG-I\002ORG-I\002ORG-I\002n-B\002n-I\002c-B\002n-B\002n-I\002ORG-B\002ORG-I\002n-B\002n-I
+除\002了\002他\002续\002任\002十\002二\002届\002政\002协\002委\002员\002,\002马\002化\002腾\002,\002雷\002军\002,\002李\002彦\002宏\002也\002被\002推\002选\002为\002新\002一\002届\002全\002国\002人\002大\002代\002表\002或\002全\002国\002政\002协\002委\002员    p-B\002p-I\002r-B\002v-B\002v-I\002m-B\002m-I\002m-I\002ORG-B\002ORG-I\002n-B\002n-I\002w-B\002PER-B\002PER-I\002PER-I\002w-B\002PER-B\002PER-I\002w-B\002PER-B\002PER-I\002PER-I\002d-B\002p-B\002v-B\002v-I\002v-B\002a-B\002m-B\002m-I\002ORG-B\002ORG-I\002ORG-I\002ORG-I\002n-B\002n-I\002c-B\002n-B\002n-I\002ORG-B\002ORG-I\002n-B\002n-I
 ```
 
 + 我们随同代码一并发布了完全版的模型和相关的依赖数据。但是，由于模型的训练数据过于庞大，我们没有发布训练数据，仅在`data`目录下放置少数样本用以示例输入数据格式。
@@ -196,6 +192,7 @@ Overall Architecture of GRU-CRF-MODEL
 ├── eval.py                               # 词法分析评估的脚本
 ├── downloads.py                      # 用于下载数据和模型的脚本
 ├── downloads.sh                      # 用于下载数据和模型的脚本
+├── sequence_tagging.yaml             # 模型训练、预测、评估相关配置参数
 └──reader.py                           # 文件读取相关函数
 ```
 
@@ -207,11 +204,11 @@ Overall Architecture of GRU-CRF-MODEL
 
 ```text
 @article{jiao2018LAC,
-	title={Chinese Lexical Analysis with Deep Bi-GRU-CRF Network},
-	author={Jiao, Zhenyu and Sun, Shuqi and Sun, Ke},
-	journal={arXiv preprint arXiv:1807.01882},
-	year={2018},
-	url={https://arxiv.org/abs/1807.01882}
+    title={Chinese Lexical Analysis with Deep Bi-GRU-CRF Network},
+    author={Jiao, Zhenyu and Sun, Shuqi and Sun, Ke},
+    journal={arXiv preprint arXiv:1807.01882},
+    year={2018},
+    url={https://arxiv.org/abs/1807.01882}
 }
 ```
 ### 如何贡献代码

examples/sequence_tagging/downloads.py

@@ -35,7 +35,7 @@ FILE_INFO = {
     },
     'MODEL': {
         'name': 'sequence_tagging_dy.tar.gz',
-        'md5': "1125d374c03c8218b6e47325dcf607e3"
+        'md5': "6ba37ceea8f1f764ba1fe227295a6a3b"
     },
 }
 

examples/sequence_tagging/eval.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-SequenceTagging network structure
+SequenceTagging eval structure
 """
 
 from __future__ import division
@@ -25,18 +25,16 @@ import math
 import argparse
 import numpy as np
 
-from train import SeqTagging
+from train import SeqTagging, ChunkEval, LacLoss
 from utils.configure import PDConfig
 from utils.check import check_gpu, check_version
-from utils.metrics import chunk_count
-from reader import LacDataset, create_lexnet_data_generator, create_dataloader
+from reader import LacDataset, LacDataLoader
 
 work_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.append(os.path.join(work_dir, "../"))
 from hapi.model import set_device, Input
 
 import paddle.fluid as fluid
-from paddle.fluid.optimizer import AdamOptimizer
 from paddle.fluid.layers.utils import flatten
 
 
@@ -44,51 +42,33 @@ def main(args):
     place = set_device(args.device)
     fluid.enable_dygraph(place) if args.dynamic else None
 
-    inputs = [Input([None, None], 'int64', name='words'), 
-              Input([None], 'int64', name='length')] 
+    inputs = [
+        Input(
+            [None, None], 'int64', name='words'), Input(
+                [None], 'int64', name='length'), Input(
+                    [None, None], 'int64', name='target')
+    ]
+    labels = [Input([None, None], 'int64', name='labels')]
 
-    feed_list = None if args.dynamic else [x.forward() for x in inputs]
     dataset = LacDataset(args)
-    eval_path = args.test_file
-
-    chunk_evaluator = fluid.metrics.ChunkEvaluator()
-    chunk_evaluator.reset()
-
-    eval_generator = create_lexnet_data_generator(
-        args, reader=dataset, file_name=eval_path, place=place, mode="test")
-
-    eval_dataset = create_dataloader(
-        eval_generator, place, feed_list=feed_list)
+    eval_dataset = LacDataLoader(args, place, phase="test")
 
     vocab_size = dataset.vocab_size
     num_labels = dataset.num_labels
-    model = SeqTagging(args, vocab_size, num_labels)
-
-    optim = AdamOptimizer(
-        learning_rate=args.base_learning_rate,
-        parameter_list=model.parameters())
+    model = SeqTagging(args, vocab_size, num_labels, mode="test")
 
     model.mode = "test"
-    model.prepare(inputs=inputs)
+    model.prepare(
+        metrics=ChunkEval(num_labels),
+        inputs=inputs,
+        labels=labels,
+        device=place)
     model.load(args.init_from_checkpoint, skip_mismatch=True)
 
-    for data in eval_dataset():
-        if len(data) == 1: 
-            batch_data = data[0]
-            targets = np.array(batch_data[2])
-        else: 
-            batch_data = data
-            targets = batch_data[2].numpy()
-        inputs_data = [batch_data[0], batch_data[1]]
-        crf_decode, length = model.test(inputs=inputs_data)
-        num_infer_chunks, num_label_chunks, num_correct_chunks = chunk_count(crf_decode, targets, length, dataset.id2label_dict)
-        chunk_evaluator.update(num_infer_chunks, num_label_chunks, num_correct_chunks)
-    
-    precision, recall, f1 = chunk_evaluator.eval()
-    print("[test] P: %.5f, R: %.5f, F1: %.5f" % (precision, recall, f1))
+    model.evaluate(eval_dataset.dataloader, batch_size=args.batch_size)
 
 
-if __name__ == '__main__': 
+if __name__ == '__main__':
     args = PDConfig(yaml_file="sequence_tagging.yaml")
     args.build()
     args.Print()

examples/sequence_tagging/predict.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-SequenceTagging network structure
+SequenceTagging predict structure
 """
 
 from __future__ import division
@@ -28,14 +28,13 @@ import numpy as np
 from train import SeqTagging
 from utils.check import check_gpu, check_version
 from utils.configure import PDConfig
-from reader import LacDataset, create_lexnet_data_generator, create_dataloader
+from reader import LacDataset, LacDataLoader
 
 work_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.append(os.path.join(work_dir, "../"))
 from hapi.model import set_device, Input
 
 import paddle.fluid as fluid
-from paddle.fluid.optimizer import AdamOptimizer
 from paddle.fluid.layers.utils import flatten
 
 
@@ -43,26 +42,18 @@ def main(args):
     place = set_device(args.device)
     fluid.enable_dygraph(place) if args.dynamic else None
 
-    inputs = [Input([None, None], 'int64', name='words'), 
-              Input([None], 'int64', name='length')]
+    inputs = [
+        Input(
+            [None, None], 'int64', name='words'), Input(
+                [None], 'int64', name='length')
+    ]
 
-    feed_list = None if args.dynamic else [x.forward() for x in inputs]
     dataset = LacDataset(args)
-    predict_path = args.predict_file
-
-    predict_generator = create_lexnet_data_generator(
-        args, reader=dataset, file_name=predict_path, place=place, mode="predict")
-
-    predict_dataset = create_dataloader(
-        predict_generator, place, feed_list=feed_list)
+    predict_dataset = LacDataLoader(args, place, phase="predict")
 
     vocab_size = dataset.vocab_size
     num_labels = dataset.num_labels
-    model = SeqTagging(args, vocab_size, num_labels)
-
-    optim = AdamOptimizer(
-        learning_rate=args.base_learning_rate,
-        parameter_list=model.parameters())
+    model = SeqTagging(args, vocab_size, num_labels, mode="predict")
 
     model.mode = "test"
     model.prepare(inputs=inputs)
@@ -70,20 +61,20 @@ def main(args):
     model.load(args.init_from_checkpoint, skip_mismatch=True)
 
     f = open(args.output_file, "wb")
-    for data in predict_dataset(): 
-        if len(data) == 1: 
+    for data in predict_dataset.dataloader:
+        if len(data) == 1:
             input_data = data[0]
-        else: 
+        else:
             input_data = data
-        results, length = model.test(inputs=flatten(input_data))
-        for i in range(len(results)): 
+        results, length = model.test_batch(inputs=flatten(input_data))
+        for i in range(len(results)):
             word_len = length[i]
-            word_ids = results[i][: word_len]
+            word_ids = results[i][:word_len]
             tags = [dataset.id2label_dict[str(id)] for id in word_ids]
             f.write("\002".join(tags) + "\n")
-        
 
-if __name__ == '__main__': 
+
+if __name__ == '__main__':
     args = PDConfig(yaml_file="sequence_tagging.yaml")
     args.build()
     args.Print()

examples/sequence_tagging/reader.py

@@ -19,12 +19,19 @@ from __future__ import division
 from __future__ import print_function
 
 import io
+import os
+import leveldb
 import numpy as np
+import shutil
+from functools import partial
 
 import paddle
+from paddle.io import BatchSampler, DataLoader, Dataset
+from paddle.fluid.dygraph.parallel import ParallelEnv
+from hapi.distributed import DistributedBatchSampler
 
 
-class LacDataset(object):
+class LacDataset(Dataset):
     """
     Load lexical analysis dataset
     """
@@ -34,6 +41,7 @@ class LacDataset(object):
         self.label_dict_path = args.label_dict_path
         self.word_rep_dict_path = args.word_rep_dict_path
         self._load_dict()
+        self.examples = []
 
     def _load_dict(self):
         self.word2id_dict = self.load_kv_dict(
@@ -108,152 +116,135 @@ class LacDataset(object):
             label_ids.append(label_id)
         return label_ids
 
-    def file_reader(self,
-                    filename,
-                    mode="train",
-                    batch_size=32,
-                    max_seq_len=126):
+    def file_reader(self, filename, phase="train"):
         """
         yield (word_idx, target_idx) one by one from file,
             or yield (word_idx, ) in `infer` mode
         """
-
-        def wrapper():
-            fread = io.open(filename, "r", encoding="utf-8")
-            if mode == "train": 
-                headline = next(fread)
-                headline = headline.strip().split('\t')
-                assert len(headline) == 2 and headline[0] == "text_a" and headline[
-                    1] == "label"
-                buf = []
-                for line in fread:
-                    words, labels = line.strip("\n").split("\t")
-                    if len(words) < 1:
-                        continue
-                    word_ids = self.word_to_ids(words.split("\002"))
-                    label_ids = self.label_to_ids(labels.split("\002"))
-                    assert len(word_ids) == len(label_ids)
-                    words_len = np.int64(len(word_ids))
-                        
-                    word_ids = word_ids[0:max_seq_len]
-                    words_len = np.int64(len(word_ids))
-                    word_ids += [0 for _ in range(max_seq_len - words_len)]
-                    label_ids = label_ids[0:max_seq_len]
-                    label_ids += [0 for _ in range(max_seq_len - words_len)]
-                    assert len(word_ids) == len(label_ids)
-                    yield word_ids, label_ids, words_len
-            elif mode == "test": 
-                headline = next(fread)
+        self.phase = phase
+        with io.open(filename, "r", encoding="utf8") as fr:
+            if phase in ["train", "test"]:
+                headline = next(fr)
                 headline = headline.strip().split('\t')
-                assert len(headline) == 2 and headline[0] == "text_a" and headline[
-                           1] == "label"
-                buf = []
-                for line in fread:
-                    words, labels = line.strip("\n").split("\t")
-                    if len(words) < 1:
-                        continue
-                    word_ids = self.word_to_ids(words.split("\002"))
-                    label_ids = self.label_to_ids(labels.split("\002"))
-                    assert len(word_ids) == len(label_ids)
-                    words_len = np.int64(len(word_ids))
-                    yield word_ids, label_ids, words_len
-            else: 
-                for line in fread: 
-                    words = line.strip("\n").split('\t')[0]
-                    if words == u"text_a": 
+                assert len(headline) == 2 and headline[
+                    0] == "text_a" and headline[1] == "label"
+
+                for line in fr:
+                    line_str = line.strip("\n")
+                    if len(line_str) < 1 and len(line_str.split('\t')) < 2:
                         continue
-                    if "\002" not in words: 
-                        word_ids = self.word_to_ids(words)
-                    else: 
-                        word_ids = self.word_to_ids(words.split("\002"))
-                    words_len = np.int64(len(word_ids))
-                    yield word_ids, words_len
 
-            fread.close()
+                    self.examples.append(line_str)
+            else:
+                for idx, line in enumerate(fr):
+                    words = line.strip("\n").split("\t")[0]
+                    self.examples.append(words)
+
+    def __getitem__(self, idx):
+        line_str = self.examples[idx]
+        if self.phase in ["train", "test"]:
+            words, labels = line_str.split('\t')
+            word_ids = self.word_to_ids(words.split("\002"))
+            label_ids = self.label_to_ids(labels.split("\002"))
+            assert len(word_ids) == len(label_ids)
+            return word_ids, label_ids
+        else:
+            words = [w for w in line_str]
+            word_ids = self.word_to_ids(words)
+            return word_ids
+
+    def __len__(self):
 
-        return wrapper
+        return len(self.examples)
 
 
-def create_lexnet_data_generator(args, reader, file_name, place, mode="train"): 
-    def padding_data(max_len, batch_data): 
+def create_lexnet_data_generator(args, insts, phase="train"):
+    def padding_data(max_len, batch_data, if_len=False):
         padding_batch_data = []
-        for data in batch_data: 
+        padding_lens = []
+        for data in batch_data:
+            data = data[:max_len]
+            if if_len:
+                seq_len = np.int64(len(data))
+                padding_lens.append(seq_len)
             data += [0 for _ in range(max_len - len(data))]
             padding_batch_data.append(data)
-        return padding_batch_data
-
-    def wrapper(): 
-        if mode == "train": 
-            batch_words, batch_labels, seq_lens = [], [], []
-            for epoch in xrange(args.epoch):
-                for instance in reader.file_reader(
-                        file_name, mode, max_seq_len=args.max_seq_len)():
-                    words, labels, words_len = instance
-                    if len(seq_lens) < args.batch_size:
-                        batch_words.append(words)
-                        batch_labels.append(labels)
-                        seq_lens.append(words_len)
-                    if len(seq_lens) == args.batch_size: 
-                        yield batch_words, seq_lens, batch_labels, batch_labels
-                        batch_words, batch_labels, seq_lens = [], [], []
-
-            if len(seq_lens) > 0:
-                yield batch_words, seq_lens, batch_labels, batch_labels
-        elif mode == "test": 
-            batch_words, batch_labels, seq_lens, max_len = [], [], [], 0
-            for instance in reader.file_reader(
-                file_name, mode, max_seq_len=args.max_seq_len)():
-                words, labels, words_len = instance
-                max_len = words_len if words_len > max_len else max_len
-                if len(seq_lens) < args.batch_size:
-                    batch_words.append(words)
-                    seq_lens.append(words_len)
-                    batch_labels.append(labels)
-                if len(seq_lens) == args.batch_size: 
-                    padding_batch_words = padding_data(max_len, batch_words)
-                    padding_batch_labels = padding_data(max_len, batch_labels)
-                    yield padding_batch_words, seq_lens, padding_batch_labels, padding_batch_labels
-                    batch_words, batch_labels, seq_lens, max_len = [], [], [], 0
-            if len(seq_lens) > 0: 
-                padding_batch_words = padding_data(max_len, batch_words)
-                padding_batch_labels = padding_data(max_len, batch_labels)
-                yield padding_batch_words, seq_lens, padding_batch_labels, padding_batch_labels
-
-        else: 
-            batch_words, seq_lens, max_len = [], [], 0
-            for instance in reader.file_reader(
-                   file_name, mode, max_seq_len=args.max_seq_len)():
-                words, words_len = instance
-                if len(seq_lens) < args.batch_size:
-                    batch_words.append(words)
-                    seq_lens.append(words_len)
-                    max_len = words_len if words_len > max_len else max_len
-                if len(seq_lens) == args.batch_size: 
-                    padding_batch_words = padding_data(max_len, batch_words)
-                    yield padding_batch_words, seq_lens
-                    batch_words, seq_lens, max_len = [], [], 0
-            if len(seq_lens) > 0: 
-                padding_batch_words = padding_data(max_len, batch_words)
-                yield padding_batch_words, seq_lens
-
-    return wrapper
-
-
-def create_dataloader(generator, place, feed_list=None):
-    if not feed_list:
-        data_loader = paddle.io.DataLoader.from_generator(
-            capacity=50,
-            use_double_buffer=True,
-            iterable=True,
-            return_list=True)
+        if if_len:
+            return np.array(padding_batch_data), np.array(padding_lens)
+        else:
+            return np.array(padding_batch_data)
+
+    if phase == "train":
+        batch_words = [inst[0] for inst in insts]
+        batch_labels = [inst[1] for inst in insts]
+        padding_batch_words, padding_lens = padding_data(
+            args.max_seq_len, batch_words, if_len=True)
+        padding_batch_labels = padding_data(args.max_seq_len, batch_labels)
+        return [
+            padding_batch_words, padding_lens, padding_batch_labels,
+            padding_batch_labels
+        ]
+    elif phase == "test":
+        batch_words = [inst[0] for inst in insts]
+        seq_len = [len(inst[0]) for inst in insts]
+        max_seq_len = max(seq_len)
+        batch_labels = [inst[1] for inst in insts]
+        padding_batch_words, padding_lens = padding_data(
+            max_seq_len, batch_words, if_len=True)
+        padding_batch_labels = padding_data(max_seq_len, batch_labels)
+        return [
+            padding_batch_words, padding_lens, padding_batch_labels,
+            padding_batch_labels
+        ]
     else:
-        data_loader = paddle.io.DataLoader.from_generator(
-            feed_list=feed_list,
-            capacity=50,
-            use_double_buffer=True,
-            iterable=True,
+        batch_words = insts
+        seq_len = [len(inst) for inst in insts]
+        max_seq_len = max(seq_len)
+        padding_batch_words, padding_lens = padding_data(
+            max_seq_len, batch_words, if_len=True)
+        return [padding_batch_words, padding_lens]
+
+
+class LacDataLoader(object):
+    def __init__(self,
+                 args,
+                 place,
+                 phase="train",
+                 shuffle=False,
+                 num_workers=0,
+                 drop_last=False):
+        assert phase in [
+            "train", "test", "predict"
+        ], "phase should be in [train, test, predict], but get %s" % phase
+
+        if phase == "train":
+            file_name = args.train_file
+        elif phase == "test":
+            file_name = args.test_file
+        elif phase == "predict":
+            file_name = args.predict_file
+
+        self.dataset = LacDataset(args)
+        self.dataset.file_reader(file_name, phase=phase)
+
+        if phase == "train":
+            self.sampler = DistributedBatchSampler(
+                dataset=self.dataset,
+                batch_size=args.batch_size,
+                shuffle=shuffle,
+                drop_last=drop_last)
+        else:
+            self.sampler = BatchSampler(
+                dataset=self.dataset,
+                batch_size=args.batch_size,
+                shuffle=shuffle,
+                drop_last=drop_last)
+
+        self.dataloader = DataLoader(
+            dataset=self.dataset,
+            batch_sampler=self.sampler,
+            places=place,
+            collate_fn=partial(
+                create_lexnet_data_generator, args, phase=phase),
+            num_workers=num_workers,
             return_list=True)
-    data_loader.set_batch_generator(generator, places=place)
-    return data_loader
-
-

examples/sequence_tagging/sequence_tagging.yaml

 word_dict_path: "./conf/word.dic"
 label_dict_path: "./conf/tag.dic"
 word_rep_dict_path: "./conf/q2b.dic"
-device: "cpu"
+device: "gpu"
 dynamic: True
 epoch: 10
 base_learning_rate: 0.001
@@ -14,7 +14,7 @@ batch_size: 300
 max_seq_len: 126
 num_devices: 1
 save_dir: "model"
-init_from_checkpoint: "model_baseline/params"
+init_from_checkpoint: ""
 init_from_pretrain_model: ""
 save_freq: 1
 eval_freq: 1
@@ -22,4 +22,3 @@ output_file: "predict.result"
 test_file: "./data/test.tsv"
 train_file: "./data/train.tsv"
 predict_file: "./data/infer.tsv"
-mode: "train"

examples/sequence_tagging/train.py

@@ -28,21 +28,23 @@ import numpy as np
 work_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.append(os.path.join(work_dir, "../"))
 
-
 from hapi.metrics import Metric
 from hapi.model import Model, Input, Loss, set_device
 from hapi.text.text import SequenceTagging
 
 from utils.check import check_gpu, check_version
 from utils.configure import PDConfig
-from reader import LacDataset, create_lexnet_data_generator, create_dataloader 
+from reader import LacDataset, LacDataLoader
 
 import paddle.fluid as fluid
 from paddle.fluid.optimizer import AdamOptimizer
 
+__all__ = ["SeqTagging", "LacLoss", "ChunkEval"]
+
 
 class SeqTagging(Model):
-    def __init__(self, args, vocab_size, num_labels, length=None):
+    def __init__(self, args, vocab_size, num_labels, length=None,
+                 mode="train"):
         super(SeqTagging, self).__init__()
         """
         define the lexical analysis network structure
@@ -53,7 +55,7 @@ class SeqTagging(Model):
             for infer: return the prediction
             otherwise: return the prediction
         """
-        self.mode_type = args.mode
+        self.mode_type = mode
         self.word_emb_dim = args.word_emb_dim
         self.vocab_size = vocab_size
         self.num_labels = num_labels
@@ -65,19 +67,19 @@ class SeqTagging(Model):
         self.bigru_num = args.bigru_num
         self.batch_size = args.batch_size
         self.init_bound = 0.1
-        self.length=length
+        self.length = length
 
         self.sequence_tagging = SequenceTagging(
-                        vocab_size=self.vocab_size,
-                        num_labels=self.num_labels,
-                        batch_size=self.batch_size,
-                        word_emb_dim=self.word_emb_dim,
-                        grnn_hidden_dim=self.grnn_hidden_dim,
-                        emb_learning_rate=self.emb_lr,
-                        crf_learning_rate=self.crf_lr,
-                        bigru_num=self.bigru_num,
-                        init_bound=self.init_bound,
-                        length=self.length)
+            vocab_size=self.vocab_size,
+            num_labels=self.num_labels,
+            batch_size=self.batch_size,
+            word_emb_dim=self.word_emb_dim,
+            grnn_hidden_dim=self.grnn_hidden_dim,
+            emb_learning_rate=self.emb_lr,
+            crf_learning_rate=self.crf_lr,
+            bigru_num=self.bigru_num,
+            init_bound=self.init_bound,
+            length=self.length)
 
     def forward(self, *inputs):
         """
@@ -85,10 +87,10 @@ class SeqTagging(Model):
         """
         word = inputs[0]
         lengths = inputs[1]
-        if self.mode_type == "train" or self.mode_type == "test": 
+        if self.mode_type == "train" or self.mode_type == "test":
             target = inputs[2]
             outputs = self.sequence_tagging(word, lengths, target)
-        else: 
+        else:
             outputs = self.sequence_tagging(word, lengths)
         return outputs
 
@@ -156,7 +158,7 @@ class ChunkEval(Metric):
             int(math.ceil((num_labels - 1) / 2.0)), "IOB")
         self.reset()
 
-    def add_metric_op(self, *args): 
+    def add_metric_op(self, *args):
         crf_decode = args[0]
         lengths = args[2]
         label = args[3]
@@ -207,30 +209,25 @@ def main(args):
     place = set_device(args.device)
     fluid.enable_dygraph(place) if args.dynamic else None
 
-    inputs = [Input([None, None], 'int64', name='words'),
-              Input([None], 'int64', name='length'), 
-              Input([None, None], 'int64', name='target')]
+    inputs = [
+        Input(
+            [None, None], 'int64', name='words'), Input(
+                [None], 'int64', name='length'), Input(
+                    [None, None], 'int64', name='target')
+    ]
 
     labels = [Input([None, None], 'int64', name='labels')]
 
-    feed_list = None if args.dynamic else [x.forward() for x in inputs + labels]
-    dataset = LacDataset(args)
-    train_path = args.train_file
-    test_path = args.test_file
-
-    train_generator = create_lexnet_data_generator(
-        args, reader=dataset, file_name=train_path, place=place, mode="train")
-    test_generator = create_lexnet_data_generator(
-        args, reader=dataset, file_name=test_path, place=place, mode="test")
+    feed_list = None if args.dynamic else [
+        x.forward() for x in inputs + labels
+    ]
 
-    train_dataset = create_dataloader(
-        train_generator, place, feed_list=feed_list)
-    test_dataset = create_dataloader(
-        test_generator, place, feed_list=feed_list)
+    dataset = LacDataset(args)
+    train_dataset = LacDataLoader(args, place, phase="train")
 
     vocab_size = dataset.vocab_size
     num_labels = dataset.num_labels
-    model = SeqTagging(args, vocab_size, num_labels)
+    model = SeqTagging(args, vocab_size, num_labels, mode="train")
 
     optim = AdamOptimizer(
         learning_rate=args.base_learning_rate,
@@ -250,8 +247,7 @@ def main(args):
     if args.init_from_pretrain_model:
         model.load(args.init_from_pretrain_model, reset_optimizer=True)
 
-    model.fit(train_dataset,
-              test_dataset,
+    model.fit(train_dataset.dataloader,
               epochs=args.epoch,
               batch_size=args.batch_size,
               eval_freq=args.eval_freq,
@@ -263,7 +259,7 @@ if __name__ == '__main__':
     args = PDConfig(yaml_file="sequence_tagging.yaml")
     args.build()
     args.Print()
-    
+
     use_gpu = True if args.device == "gpu" else False
     check_gpu(use_gpu)
     check_version()

examples/sequence_tagging/utils/configure.py

@@ -195,13 +195,19 @@ class PDConfig(object):
                                "Whether to perform predicting.")
         self.default_g.add_arg("do_eval", bool, False,
                                "Whether to perform evaluating.")
-        self.default_g.add_arg("do_save_inference_model", bool, False,
-                               "Whether to perform model saving for inference.")
+        self.default_g.add_arg(
+            "do_save_inference_model", bool, False,
+            "Whether to perform model saving for inference.")
 
         # NOTE: args for profiler
-        self.default_g.add_arg("is_profiler", int, 0, "the switch of profiler tools. (used for benchmark)")
-        self.default_g.add_arg("profiler_path", str, './', "the profiler output file path. (used for benchmark)")
-        self.default_g.add_arg("max_iter", int, 0, "the max train batch num.(used for benchmark)")
+        self.default_g.add_arg(
+            "is_profiler", int, 0,
+            "the switch of profiler tools. (used for benchmark)")
+        self.default_g.add_arg(
+            "profiler_path", str, './',
+            "the profiler output file path. (used for benchmark)")
+        self.default_g.add_arg("max_iter", int, 0,
+                               "the max train batch num.(used for benchmark)")
 
         self.parser = parser
 

examples/sequence_tagging/utils/metrics.py

@@ -23,7 +23,7 @@ import paddle.fluid as fluid
 __all__ = ['chunk_count', "build_chunk"]
 
 
-def build_chunk(data_list, id2label_dict): 
+def build_chunk(data_list, id2label_dict):
     """
     Assembly entity
     """
@@ -31,29 +31,29 @@ def build_chunk(data_list, id2label_dict):
     ner_dict = {}
     ner_str = ""
     ner_start = 0
-    for i in range(len(tag_list)): 
+    for i in range(len(tag_list)):
         tag = tag_list[i]
-        if tag == u"O": 
-            if i != 0: 
+        if tag == u"O":
+            if i != 0:
                 key = "%d_%d" % (ner_start, i - 1)
                 ner_dict[key] = ner_str
             ner_start = i
-            ner_str = tag 
-        elif tag.endswith(u"B"): 
-            if i != 0: 
+            ner_str = tag
+        elif tag.endswith(u"B"):
+            if i != 0:
                 key = "%d_%d" % (ner_start, i - 1)
                 ner_dict[key] = ner_str
             ner_start = i
             ner_str = tag.split('-')[0]
-        elif tag.endswith(u"I"): 
-            if tag.split('-')[0] != ner_str: 
-                if i != 0: 
+        elif tag.endswith(u"I"):
+            if tag.split('-')[0] != ner_str:
+                if i != 0:
                     key = "%d_%d" % (ner_start, i - 1)
                     ner_dict[key] = ner_str
                 ner_start = i
                 ner_str = tag.split('-')[0]
     return ner_dict
-                    
+
 
 def chunk_count(infer_numpy, label_numpy, seq_len, id2label_dict):
     """
@@ -62,15 +62,14 @@ def chunk_count(infer_numpy, label_numpy, seq_len, id2label_dict):
     num_infer_chunks, num_label_chunks, num_correct_chunks = 0, 0, 0
     assert infer_numpy.shape[0] == label_numpy.shape[0]
 
-    for i in range(infer_numpy.shape[0]): 
-        infer_list = infer_numpy[i][: seq_len[i]]
-        label_list = label_numpy[i][: seq_len[i]]
+    for i in range(infer_numpy.shape[0]):
+        infer_list = infer_numpy[i][:seq_len[i]]
+        label_list = label_numpy[i][:seq_len[i]]
         infer_dict = build_chunk(infer_list, id2label_dict)
         num_infer_chunks += len(infer_dict)
         label_dict = build_chunk(label_list, id2label_dict)
         num_label_chunks += len(label_dict)
-        for key in infer_dict: 
-            if key in label_dict and label_dict[key] == infer_dict[key]: 
+        for key in infer_dict:
+            if key in label_dict and label_dict[key] == infer_dict[key]:
                 num_correct_chunks += 1
     return num_infer_chunks, num_label_chunks, num_correct_chunks
-

examples/style-transfer/README.md

+# 图像风格迁移
+
+图像的风格迁移是卷积神经网络有趣的应用之一。那什么是风格迁移呢？下图第一列左边的图为相机拍摄的一张普通图片，右边的图为梵高的名画星空。那如何让左边的普通图片拥有星空的风格呢。神经网络的风格迁移就可以帮助你生成第二列的这样的图片。
+
+<div align=center>
+ <img src="images/markdown/img1.png" width = "600" height = "300"  />
+</br>
+ <img src="images/markdown/img2.png" width = "300" height = "300"  divalign=center />
+<div align=left>
+
+
+## 基本原理
+风格迁移的目标就是使得生成图片的内容与内容图片（content image）尽可能相似。由于在计算机中，我们用一个一个像素点表示图片，所以两个图片的相似程度我们可以用每个像素点的欧式距离来表示。而两个图片的风格相似度，我们采用两个图片在卷积神经网络中相同的一层特征图的gram矩阵的欧式距离来表示。对于一个特征图gram矩阵的计算如下所示：
+
+```python
+# tensor shape is [1, c, h, w]
+_, c, h, w = tensor.shape
+tensor = fluid.layers.reshape(tensor, [c, h * w])
+# gram matrix with shape: [c, c]
+gram_matrix = fluid.layers.matmul(tensor, fluid.layers.transpose(tensor, [1, 0]))
+```
+
+最终风格迁移的问题转化为优化上述的两个欧式距离的问题。这里要注意的是，我们使用一个在imagenet上预训练好的模型vgg16，并且固定参数，优化器只更新输入的生成图像的值。
+
+## 具体实现
+接下来，使用代码一步一步来实现上述图片的风格迁移
+
+```python
+# 导入所需的模块
+%matplotlib inline
+
+import numpy as np
+import matplotlib.pyplot as plt
+
+from hapi.model import Model, Loss
+
+from hapi.vision.models import vgg16
+from hapi.vision.transforms import transforms
+from paddle import fluid
+from paddle.fluid.io import Dataset
+
+import cv2
+import copy
+
+# 图像预处理函数，和tensor恢复到自然图像的函数
+from .style_transfer import load_image, image_restore
+```
+
+
+```python
+# 启动动态图模式
+fluid.enable_dygraph()
+```
+
+```python
+# 内容图像，用于风格迁移
+content_path = './images/chicago_cropped.jpg'
+# 风格图像
+style_path = './images/Starry-Night-by-Vincent-Van-Gogh-painting.jpg'
+```
+
+
+```python
+# 可视化两个图像
+content = load_image(content_path)
+style = load_image(style_path, shape=tuple(content.shape[-2:]))
+
+fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(10, 10))
+ax1.imshow(image_restore(content))
+ax2.imshow(image_restore(style))
+```
+
+
+![png](images/markdown/output_10_1.png)
+
+
+
+```python
+# 定义风格迁移模型，使用在imagenet上预训练好的vgg16作为基础模型
+class StyleTransferModel(Model):
+    def __init__(self):
+        super(StyleTransferModel, self).__init__()
+        # pretrained设置为true，会自动下载imagenet上的预训练权重并加载
+        vgg = vgg16(pretrained=True)
+        self.base_model = vgg.features
+        for p in self.base_model.parameters():
+            p.stop_gradient=True
+        self.layers = {
+                  '0': 'conv1_1',
+                  '3': 'conv2_1',
+                  '6': 'conv3_1',
+                  '10': 'conv4_1',
+                  '11': 'conv4_2',  ## content representation
+                  '14': 'conv5_1'
+                 }
+
+    def forward(self, image):
+        outputs = []
+        for name, layer in self.base_model.named_sublayers():
+            image = layer(image)
+            if name in self.layers:
+                outputs.append(image)
+        return outputs
+```
+
+
+```python
+# 定义风格迁移个损失函数
+class StyleTransferLoss(Loss):
+    def __init__(self, content_loss_weight=1, style_loss_weight=1e5, style_weights=[1.0, 0.8, 0.5, 0.3, 0.1]):
+        super(StyleTransferLoss, self).__init__()
+        self.content_loss_weight = content_loss_weight
+        self.style_loss_weight = style_loss_weight
+        self.style_weights = style_weights
+
+    def forward(self, outputs, labels):
+        content_features = labels[-1]
+        style_features = labels[:-1]
+
+        # 计算图像内容相似度的loss
+        content_loss = fluid.layers.mean((outputs[-2] - content_features)**2)
+
+        # 计算风格相似度的loss
+        style_loss = 0
+        style_grams = [self.gram_matrix(feat) for feat in style_features ]
+        style_weights = self.style_weights
+        for i, weight in enumerate(style_weights):
+            target_gram = self.gram_matrix(outputs[i])
+            layer_loss = weight * fluid.layers.mean((target_gram - style_grams[i])**2)
+            b, d, h, w = outputs[i].shape
+            style_loss += layer_loss / (d * h * w)
+
+        total_loss = self.content_loss_weight * content_loss + self.style_loss_weight * style_loss
+        return total_loss
+
+    def gram_matrix(self, A):
+        if len(A.shape) == 4:
+            batch_size, c, h, w = A.shape
+            A = fluid.layers.reshape(A, (c, h*w))
+        GA = fluid.layers.matmul(A, fluid.layers.transpose(A, [1, 0]))
+
+        return GA
+```
+
+
+```python
+# 创建模型
+model = StyleTransferModel()
+```
+
+
+```python
+# 创建损失函数
+style_loss = StyleTransferLoss()
+```
+
+
+```python
+# 使用内容图像初始化要生成的图像
+target = Model.create_parameter(model, shape=content.shape)
+target.set_value(content.numpy())
+```
+
+
+```python
+# 创建优化器
+optimizer = fluid.optimizer.Adam(parameter_list=[target], learning_rate=0.001)
+```
+
+
+```python
+# 初始化高级api
+model.prepare(optimizer, style_loss)
+```
+
+
+```python
+# 使用内容图像和风格图像获取内容特征和风格特征
+content_fetures = model.test_batch(content)
+style_features = model.test_batch(style)
+```
+
+
+```python
+# 将两个特征组合，作为损失函数的label传给模型
+feats = style_features + [content_fetures[-2]]
+```
+
+
+```python
+# 训练5000个step，每500个step画一下生成的图像查看效果
+steps = 5000
+for i in range(steps):
+    outs = model.train_batch(target, feats)
+
+    if i % 500 == 0:
+        print('iters:', i, 'loss:', outs[0])
+        plt.imshow(image_restore(target))
+        plt.show()
+```
+
+    iters: 0 loss: [8.829961e+09]
+
+
+
+![png](images/markdown/output_20_1.png)
+
+
+    iters: 500 loss: [3.728548e+08]
+
+
+
+![png](images/markdown/output_20_3.png)
+
+
+    iters: 1000 loss: [1.6327214e+08]
+
+
+
+![png](images/markdown/output_20_5.png)
+
+
+    iters: 1500 loss: [1.0806553e+08]
+
+
+
+![png](images/markdown/output_20_7.png)
+
+
+    iters: 2000 loss: [81069480.]
+
+
+
+![png](images/markdown/output_20_9.png)
+
+
+    iters: 2500 loss: [64284104.]
+
+
+
+![png](images/markdown/output_20_11.png)
+
+
+    iters: 3000 loss: [52580884.]
+
+
+
+![png](images/markdown/output_20_13.png)
+
+
+    iters: 3500 loss: [43825304.]
+
+
+
+![png](images/markdown/output_20_15.png)
+
+
+    iters: 4000 loss: [37048400.]
+
+
+
+![png](images/markdown/output_20_17.png)
+
+
+    iters: 4500 loss: [31719670.]
+
+
+
+![png](images/markdown/output_20_19.png)
+
+
+
+```python
+# 风格迁移后的图像
+fig, (ax1, ax2, ax3) = plt.subplots(1, 3, figsize=(20, 10))
+ax1.imshow(image_restore(content))
+ax2.imshow(image_restore(target))
+ax3.imshow(image_restore(style))
+```
+
+
+
+
+![png](images/markdown/output_21_1.png)
+
+
+
+## 总结
+上述可运行的代码都在[style-transfer.ipynb](./style-transfer.ipynb)中， 同时我们提供了[style-transfer.py](./style-transfer.py)脚本，可以直接执行如下命令，实现图片的风格迁移：
+
+```shell
+python -u style-transfer.py --content-image /path/to/your-content-image --style-image /path/to/your-style-image --save-dir /path/to/your-output-dir
+```
+
+风格迁移生成的图像保存在```--save-dir```中。
+
+## 参考
+
+[A Neural Algorithm of Artistic Style](https://arxiv.org/abs/1508.06576)

examples/style-transfer/style_transfer.py

+import os
+import argparse
+import numpy as np
+import matplotlib.pyplot as plt
+
+from hapi.model import Model, Loss
+
+from hapi.vision.models import vgg16
+from hapi.vision.transforms import transforms
+from paddle import fluid
+from paddle.fluid.io import Dataset
+
+import cv2
+import copy
+
+
+def load_image(image_path, max_size=400, shape=None):
+    image = cv2.imread(image_path)
+    image = image.astype('float32') / 255.0
+    size = shape if shape is not None else max_size if max(
+        image.shape[:2]) > max_size else max(image.shape[:2])
+
+    transform = transforms.Compose([
+        transforms.Resize(size), transforms.Permute(),
+        transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225])
+    ])
+    image = transform(image)[np.newaxis, :3, :, :]
+    image = fluid.dygraph.to_variable(image)
+    return image
+
+
+def image_restore(image):
+    image = np.squeeze(image.numpy(), 0)
+    image = image.transpose(1, 2, 0)
+    image = image * np.array((0.229, 0.224, 0.225)) + np.array(
+        (0.485, 0.456, 0.406))
+
+    image = image.clip(0, 1)
+    return image
+
+
+class StyleTransferModel(Model):
+    def __init__(self):
+        super(StyleTransferModel, self).__init__()
+        # pretrained设置为true，会自动下载imagenet上的预训练权重并加载
+        vgg = vgg16(pretrained=True)
+        self.base_model = vgg.features
+        for p in self.base_model.parameters():
+            p.stop_gradient = True
+        self.layers = {
+            '0': 'conv1_1',
+            '3': 'conv2_1',
+            '6': 'conv3_1',
+            '10': 'conv4_1',
+            '11': 'conv4_2',  ## content representation
+            '14': 'conv5_1'
+        }
+
+    def forward(self, image):
+        outputs = []
+        for name, layer in self.base_model.named_sublayers():
+            image = layer(image)
+            if name in self.layers:
+                outputs.append(image)
+        return outputs
+
+
+class StyleTransferLoss(Loss):
+    def __init__(self,
+                 content_loss_weight=1,
+                 style_loss_weight=1e5,
+                 style_weights=[1.0, 0.8, 0.5, 0.3, 0.1]):
+        super(StyleTransferLoss, self).__init__()
+        self.content_loss_weight = content_loss_weight
+        self.style_loss_weight = style_loss_weight
+        self.style_weights = style_weights
+
+    def forward(self, outputs, labels):
+        content_features = labels[-1]
+        style_features = labels[:-1]
+
+        # 计算图像内容相似度的loss
+        content_loss = fluid.layers.mean((outputs[-2] - content_features)**2)
+
+        # 计算风格相似度的loss
+        style_loss = 0
+        style_grams = [self.gram_matrix(feat) for feat in style_features]
+        style_weights = self.style_weights
+        for i, weight in enumerate(style_weights):
+            target_gram = self.gram_matrix(outputs[i])
+            layer_loss = weight * fluid.layers.mean((target_gram - style_grams[
+                i])**2)
+            b, d, h, w = outputs[i].shape
+            style_loss += layer_loss / (d * h * w)
+
+        total_loss = self.content_loss_weight * content_loss + self.style_loss_weight * style_loss
+        return total_loss
+
+    def gram_matrix(self, A):
+        if len(A.shape) == 4:
+            _, c, h, w = A.shape
+            A = fluid.layers.reshape(A, (c, h * w))
+        GA = fluid.layers.matmul(A, fluid.layers.transpose(A, [1, 0]))
+
+        return GA
+
+
+def main():
+    # 启动动态图模式
+    fluid.enable_dygraph()
+
+    content = load_image(FLAGS.content_image)
+    style = load_image(FLAGS.style_image, shape=tuple(content.shape[-2:]))
+
+    model = StyleTransferModel()
+    style_loss = StyleTransferLoss()
+
+    # 使用内容图像初始化要生成的图像
+    target = Model.create_parameter(model, shape=content.shape)
+    target.set_value(content.numpy())
+
+    optimizer = fluid.optimizer.Adam(
+        parameter_list=[target], learning_rate=FLAGS.lr)
+    model.prepare(optimizer, style_loss)
+
+    content_fetures = model.test_batch(content)
+    style_features = model.test_batch(style)
+
+    # 将两个特征组合，作为损失函数的label传给模型
+    feats = style_features + [content_fetures[-2]]
+
+    # 训练5000个step，每500个step画一下生成的图像查看效果
+    steps = FLAGS.steps
+    for i in range(steps):
+        outs = model.train_batch(target, feats)
+        if i % 500 == 0:
+            print('iters:', i, 'loss:', outs[0][0])
+
+    if not os.path.exists(FLAGS.save_dir):
+        os.makedirs(FLAGS.save_dir)
+
+    # 保存生成好的图像
+    name = FLAGS.content_image.split(os.sep)[-1]
+    output_path = os.path.join(FLAGS.save_dir, 'generated_' + name)
+    cv2.imwrite(output_path,
+                cv2.cvtColor((image_restore(target) * 255).astype('uint8'),
+                             cv2.COLOR_RGB2BGR))
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser("Resnet Training on ImageNet")
+    parser.add_argument(
+        "--content-image",
+        type=str,
+        default='./images/chicago_cropped.jpg',
+        help="content image")
+    parser.add_argument(
+        "--style-image",
+        type=str,
+        default='./images/Starry-Night-by-Vincent-Van-Gogh-painting.jpg',
+        help="style image")
+    parser.add_argument(
+        "--save-dir", type=str, default='./output', help="output dir")
+    parser.add_argument(
+        "--steps", default=5000, type=int, help="number of steps to run")
+    parser.add_argument(
+        '--lr',
+        '--learning-rate',
+        default=1e-3,
+        type=float,
+        metavar='LR',
+        help='initial learning rate')
+    FLAGS = parser.parse_args()
+    main()

transformer/README.md → examples/transformer/README.md

@@ -201,7 +201,7 @@ python -u predict.py \
   --special_token '<s>' '<e>' '<unk>' \
   --predict_file gen_data/wmt16_ende_data_bpe/newstest2014.tok.bpe.32000.en-de \
   --batch_size 32 \
-  --init_from_params base_model_dygraph/step_100000/transformer \
+  --init_from_params big_model_dygraph/step_100000/transformer \
   --beam_size 5 \
   --max_out_len 255 \
   --output_file predict.txt \

transformer/predict.py → examples/transformer/predict.py

@@ -14,9 +14,6 @@
 
 import logging
 import os
-import six
-import sys
-sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 from functools import partial
 
 import numpy as np
@@ -28,9 +25,9 @@ from paddle.fluid.layers.utils import flatten
 from utils.configure import PDConfig
 from utils.check import check_gpu, check_version
 
-from model import Input, set_device
+from hapi.model import Input, set_device
 from reader import prepare_infer_input, Seq2SeqDataset, Seq2SeqBatchSampler
-from transformer import InferTransformer, position_encoding_init
+from transformer import InferTransformer
 
 
 def post_process_seq(seq, bos_idx, eos_idx, output_bos=False,
@@ -132,7 +129,7 @@ def do_predict(args):
     # TODO: use model.predict when support variant length
     f = open(args.output_file, "wb")
     for data in data_loader():
-        finished_seq = transformer.test(inputs=flatten(data))[0]
+        finished_seq = transformer.test_batch(inputs=flatten(data))[0]
         finished_seq = np.transpose(finished_seq, [0, 2, 1])
         for ins in finished_seq:
             for beam_idx, beam in enumerate(ins):

transformer/reader.py → examples/transformer/reader.py

@@ -13,7 +13,7 @@
 # limitations under the License.
 
 import glob
-import six
+import sys
 import os
 import io
 import itertools
@@ -26,7 +26,7 @@ from paddle.io import BatchSampler, DataLoader, Dataset
 
 
 def create_data_loader(args, device):
-    data_loaders = [None, None]
+    data_loaders = [(None, None)] * 2
     data_files = [args.training_file, args.validation_file
                   ] if args.validation_file else [args.training_file]
     for i, data_file in enumerate(data_files):
@@ -65,7 +65,7 @@ def create_data_loader(args, device):
                 n_head=args.n_head),
             num_workers=0,  # TODO: use multi-process
             return_list=True)
-        data_loaders[i] = data_loader
+        data_loaders[i] = (data_loader, batch_sampler.__len__)
     return data_loaders
 
 
@@ -289,7 +289,6 @@ class Seq2SeqDataset(Dataset):
                  start_mark="<s>",
                  end_mark="<e>",
                  unk_mark="<unk>",
-                 only_src=False,
                  trg_fpattern=None,
                  byte_data=False):
         if byte_data:
@@ -477,6 +476,7 @@ class Seq2SeqBatchSampler(BatchSampler):
                 for i in range(self._nranks)
             ] for batch in batches]
             batches = list(itertools.chain.from_iterable(batches))
+        self.batch_number = (len(batches) + self._nranks - 1) // self._nranks
 
         # for multi-device
         for batch_id, batch in enumerate(batches):
@@ -490,11 +490,13 @@ class Seq2SeqBatchSampler(BatchSampler):
                 yield batch_indices
 
     def __len__(self):
+        if hasattr(self, "batch_number"):  #
+            return self.batch_number
         if not self._use_token_batch:
             batch_number = (
                 len(self._dataset) + self._batch_size * self._nranks - 1) // (
                     self._batch_size * self._nranks)
         else:
-            # TODO(guosheng): fix the uncertain length
-            batch_number = 1
+            # for uncertain batch number, the actual value is self.batch_number
+            batch_number = sys.maxsize
         return batch_number

transformer/train.py → examples/transformer/train.py

@@ -14,9 +14,6 @@
 
 import logging
 import os
-import six
-import sys
-sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 import numpy as np
 import paddle
@@ -26,14 +23,18 @@ from paddle.io import DataLoader
 from utils.configure import PDConfig
 from utils.check import check_gpu, check_version
 
-from model import Input, set_device
-from callbacks import ProgBarLogger
+from hapi.model import Input, set_device
+from hapi.callbacks import ProgBarLogger
 from reader import create_data_loader
 from transformer import Transformer, CrossEntropyCriterion
 
 
 class TrainCallback(ProgBarLogger):
-    def __init__(self, args, verbose=2):
+    def __init__(self,
+                 args,
+                 verbose=2,
+                 train_steps_fn=None,
+                 eval_steps_fn=None):
         # TODO(guosheng): save according to step
         super(TrainCallback, self).__init__(args.print_step, verbose)
         # the best cross-entropy value with label smoothing
@@ -42,11 +43,17 @@ class TrainCallback(ProgBarLogger):
                 (1. - args.label_smooth_eps)) + args.label_smooth_eps *
             np.log(args.label_smooth_eps / (args.trg_vocab_size - 1) + 1e-20))
         self.loss_normalizer = loss_normalizer
+        self.train_steps_fn = train_steps_fn
+        self.eval_steps_fn = eval_steps_fn
 
     def on_train_begin(self, logs=None):
         super(TrainCallback, self).on_train_begin(logs)
         self.train_metrics += ["normalized loss", "ppl"]
 
+    def on_train_batch_begin(self, step, logs=None):
+        if step == 0 and self.train_steps_fn:
+            self.train_progbar._num = self.train_steps_fn()
+
     def on_train_batch_end(self, step, logs=None):
         logs["normalized loss"] = logs["loss"][0] - self.loss_normalizer
         logs["ppl"] = np.exp(min(logs["loss"][0], 100))
@@ -57,6 +64,10 @@ class TrainCallback(ProgBarLogger):
         self.eval_metrics = list(
             self.eval_metrics) + ["normalized loss", "ppl"]
 
+    def on_eval_batch_begin(self, step, logs=None):
+        if step == 0 and self.eval_steps_fn:
+            self.eval_progbar._num = self.eval_steps_fn()
+
     def on_eval_batch_end(self, step, logs=None):
         logs["normalized loss"] = logs["loss"][0] - self.loss_normalizer
         logs["ppl"] = np.exp(min(logs["loss"][0], 100))
@@ -104,7 +115,8 @@ def do_train(args):
     ]
 
     # def dataloader
-    train_loader, eval_loader = create_data_loader(args, device)
+    (train_loader, train_steps_fn), (
+        eval_loader, eval_steps_fn) = create_data_loader(args, device)
 
     # define model
     transformer = Transformer(
@@ -142,7 +154,12 @@ def do_train(args):
                     eval_freq=1,
                     save_freq=1,
                     save_dir=args.save_model,
-                    callbacks=[TrainCallback(args)])
+                    callbacks=[
+                        TrainCallback(
+                            args,
+                            train_steps_fn=train_steps_fn,
+                            eval_steps_fn=eval_steps_fn)
+                    ])
 
 
 if __name__ == "__main__":

transformer/transformer.py → examples/transformer/transformer.py

@@ -20,8 +20,8 @@ import paddle.fluid as fluid
 import paddle.fluid.layers as layers
 from paddle.fluid.dygraph import Embedding, LayerNorm, Linear, Layer, to_variable
 from paddle.fluid.dygraph.learning_rate_scheduler import LearningRateDecay
-from model import Model, CrossEntropy, Loss
-from text import TransformerBeamSearchDecoder, DynamicDecode
+from hapi.model import Model, CrossEntropy, Loss
+from hapi.text import TransformerBeamSearchDecoder, DynamicDecode
 
 
 def position_encoding_init(n_position, d_pos_vec):

transformer/utils/configure.py → examples/transformer/utils/configure.py

@@ -195,13 +195,19 @@ class PDConfig(object):
                                "Whether to perform predicting.")
         self.default_g.add_arg("do_eval", bool, False,
                                "Whether to perform evaluating.")
-        self.default_g.add_arg("do_save_inference_model", bool, False,
-                               "Whether to perform model saving for inference.")
+        self.default_g.add_arg(
+            "do_save_inference_model", bool, False,
+            "Whether to perform model saving for inference.")
 
         # NOTE: args for profiler
-        self.default_g.add_arg("is_profiler", int, 0, "the switch of profiler tools. (used for benchmark)")
-        self.default_g.add_arg("profiler_path", str, './', "the profiler output file path. (used for benchmark)")
-        self.default_g.add_arg("max_iter", int, 0, "the max train batch num.(used for benchmark)")
+        self.default_g.add_arg(
+            "is_profiler", int, 0,
+            "the switch of profiler tools. (used for benchmark)")
+        self.default_g.add_arg(
+            "profiler_path", str, './',
+            "the profiler output file path. (used for benchmark)")
+        self.default_g.add_arg("max_iter", int, 0,
+                               "the max train batch num.(used for benchmark)")
 
         self.parser = parser
 

examples/yolov3/main.py

@@ -27,7 +27,7 @@ from paddle.io import DataLoader
 
 from hapi.model import Model, Input, set_device
 from hapi.distributed import DistributedBatchSampler
-from hapi.vision.transforms import Compose, BatchCompose
+from hapi.vision.transforms import BatchCompose
 
 from modeling import yolov3_darknet53, YoloLoss
 from coco import COCODataset
@@ -43,10 +43,9 @@ def make_optimizer(step_per_epoch, parameter_list=None):
     momentum = 0.9
     weight_decay = 5e-4
     boundaries = [step_per_epoch * e for e in [200, 250]]
-    values = [base_lr * (0.1 ** i) for i in range(len(boundaries) + 1)]
+    values = [base_lr * (0.1**i) for i in range(len(boundaries) + 1)]
     learning_rate = fluid.layers.piecewise_decay(
-        boundaries=boundaries,
-        values=values)
+        boundaries=boundaries, values=values)
     learning_rate = fluid.layers.linear_lr_warmup(
         learning_rate=learning_rate,
         warmup_steps=warm_up_iter,
@@ -63,77 +62,88 @@ def make_optimizer(step_per_epoch, parameter_list=None):
 def main():
     device = set_device(FLAGS.device)
     fluid.enable_dygraph(device) if FLAGS.dynamic else None
-    
-    inputs = [Input([None, 1], 'int64', name='img_id'),
-              Input([None, 2], 'int32', name='img_shape'),
-              Input([None, 3, None, None], 'float32', name='image')]
-    labels = [Input([None, NUM_MAX_BOXES, 4], 'float32', name='gt_bbox'),
-	      Input([None, NUM_MAX_BOXES], 'int32', name='gt_label'),
-	      Input([None, NUM_MAX_BOXES], 'float32', name='gt_score')]
-
-    if not FLAGS.eval_only: # training mode
-        train_transform = Compose([ColorDistort(),
-                                   RandomExpand(),
-                                   RandomCrop(),
-                                   RandomFlip(),
-                                   NormalizeBox(),
-                                   PadBox(),
-                                   BboxXYXY2XYWH()])
+
+    inputs = [
+        Input(
+            [None, 1], 'int64', name='img_id'), Input(
+                [None, 2], 'int32', name='img_shape'), Input(
+                    [None, 3, None, None], 'float32', name='image')
+    ]
+
+    labels = [
+        Input(
+            [None, NUM_MAX_BOXES, 4], 'float32', name='gt_bbox'), Input(
+                [None, NUM_MAX_BOXES], 'int32', name='gt_label'), Input(
+                    [None, NUM_MAX_BOXES], 'float32', name='gt_score')
+    ]
+
+    if not FLAGS.eval_only:  # training mode
+        train_transform = Compose([
+            ColorDistort(), RandomExpand(), RandomCrop(), RandomFlip(),
+            NormalizeBox(), PadBox(), BboxXYXY2XYWH()
+        ])
+
         train_collate_fn = BatchCompose([RandomShape(), NormalizeImage()])
-        dataset = COCODataset(dataset_dir=FLAGS.data,
-                              anno_path='annotations/instances_train2017.json',
-                              image_dir='train2017',
-                              with_background=False,
-                              mixup=True,
-                              transform=train_transform)
-        batch_sampler = DistributedBatchSampler(dataset,
-                                                batch_size=FLAGS.batch_size,
-                                                shuffle=True,
-                                                drop_last=True)
-        loader = DataLoader(dataset,
-                            batch_sampler=batch_sampler,
-                            places=device,
-                            num_workers=FLAGS.num_workers,
-                            return_list=True,
-                            collate_fn=train_collate_fn)
-    else: # evaluation mode
-        eval_transform = Compose([ResizeImage(target_size=608),
-                                  NormalizeBox(),
-                                  PadBox(),
-                                  BboxXYXY2XYWH()])
+        dataset = COCODataset(
+            dataset_dir=FLAGS.data,
+            anno_path='annotations/instances_train2017.json',
+            image_dir='train2017',
+            with_background=False,
+            mixup=True,
+            transform=train_transform)
+        batch_sampler = DistributedBatchSampler(
+            dataset, batch_size=FLAGS.batch_size, shuffle=True, drop_last=True)
+        loader = DataLoader(
+            dataset,
+            batch_sampler=batch_sampler,
+            places=device,
+            num_workers=FLAGS.num_workers,
+            return_list=True,
+            collate_fn=train_collate_fn)
+    else:  # evaluation mode
+        eval_transform = Compose([
+            ResizeImage(target_size=608), NormalizeBox(), PadBox(),
+            BboxXYXY2XYWH()
+        ])
+
         eval_collate_fn = BatchCompose([NormalizeImage()])
-        dataset = COCODataset(dataset_dir=FLAGS.data,
-                              anno_path='annotations/instances_val2017.json',
-                              image_dir='val2017',
-                              with_background=False,
-                              transform=eval_transform)
+        dataset = COCODataset(
+            dataset_dir=FLAGS.data,
+            anno_path='annotations/instances_val2017.json',
+            image_dir='val2017',
+            with_background=False,
+            transform=eval_transform)
         # batch_size can only be 1 in evaluation for YOLOv3
         # prediction bbox is a LoDTensor
-        batch_sampler = DistributedBatchSampler(dataset,
-                                                batch_size=1,
-                                                shuffle=False,
-                                                drop_last=False)
-        loader = DataLoader(dataset,
-                            batch_sampler=batch_sampler,
-                            places=device,
-                            num_workers=FLAGS.num_workers,
-                            return_list=True,
-                            collate_fn=eval_collate_fn)
+        batch_sampler = DistributedBatchSampler(
+            dataset, batch_size=1, shuffle=False, drop_last=False)
+        loader = DataLoader(
+            dataset,
+            batch_sampler=batch_sampler,
+            places=device,
+            num_workers=FLAGS.num_workers,
+            return_list=True,
+            collate_fn=eval_collate_fn)
 
     pretrained = FLAGS.eval_only and FLAGS.weights is None
-    model = yolov3_darknet53(num_classes=dataset.num_classes,
-                   model_mode='eval' if FLAGS.eval_only else 'train',
-                   pretrained=pretrained)
+    model = yolov3_darknet53(
+        num_classes=dataset.num_classes,
+        model_mode='eval' if FLAGS.eval_only else 'train',
+        pretrained=pretrained)
 
     if FLAGS.pretrain_weights and not FLAGS.eval_only:
-        model.load(FLAGS.pretrain_weights, skip_mismatch=True, reset_optimizer=True)
+        model.load(
+            FLAGS.pretrain_weights, skip_mismatch=True, reset_optimizer=True)
 
-    optim = make_optimizer(len(batch_sampler), parameter_list=model.parameters())
+    optim = make_optimizer(
+        len(batch_sampler), parameter_list=model.parameters())
 
-    model.prepare(optim,
-                  YoloLoss(num_classes=dataset.num_classes),
-                  inputs=inputs, labels=labels,
-                  device=FLAGS.device)
+    model.prepare(
+        optim,
+        YoloLoss(num_classes=dataset.num_classes),
+        inputs=inputs,
+        labels=labels,
+        device=FLAGS.device)
 
     # NOTE: we implement COCO metric of YOLOv3 model here, separately
     # from 'prepare' and 'fit' framework for follwing reason:
@@ -149,7 +159,8 @@ def main():
         preds = model.predict(loader, stack_outputs=False)
         _, _, _, img_ids, bboxes = preds
 
-        anno_path = os.path.join(FLAGS.data, 'annotations/instances_val2017.json')
+        anno_path = os.path.join(FLAGS.data,
+                                 'annotations/instances_val2017.json')
         coco_metric = COCOMetric(anno_path=anno_path, with_background=False)
         for img_id, bbox in zip(img_ids, bboxes):
             coco_metric.update(img_id, bbox)
@@ -176,7 +187,9 @@ def main():
 if __name__ == '__main__':
     parser = argparse.ArgumentParser("Yolov3 Training on VOC")
     parser.add_argument(
-        "--data", type=str, default='dataset/voc',
+        "--data",
+        type=str,
+        default='dataset/voc',
         help="path to dataset directory")
     parser.add_argument(
         "--device", type=str, default='gpu', help="device to use, gpu or cpu")
@@ -187,23 +200,38 @@ if __name__ == '__main__':
     parser.add_argument(
         "-e", "--epoch", default=300, type=int, help="number of epoch")
     parser.add_argument(
-        "--no_mixup_epoch", default=30, type=int,
+        "--no_mixup_epoch",
+        default=30,
+        type=int,
         help="number of the last N epoch without image mixup")
     parser.add_argument(
-        '--lr', '--learning-rate', default=0.001, type=float, metavar='LR',
+        '--lr',
+        '--learning-rate',
+        default=0.001,
+        type=float,
+        metavar='LR',
         help='initial learning rate')
     parser.add_argument(
         "-b", "--batch_size", default=8, type=int, help="batch size")
     parser.add_argument(
-        "-j", "--num_workers", default=4, type=int, help="reader worker number")
+        "-j",
+        "--num_workers",
+        default=4,
+        type=int,
+        help="reader worker number")
     parser.add_argument(
-        "-p", "--pretrain_weights", default=None, type=str,
+        "-p",
+        "--pretrain_weights",
+        default=None,
+        type=str,
         help="path to pretrained weights")
     parser.add_argument(
-        "-r", "--resume", default=None, type=str,
-        help="path to model weights")
+        "-r", "--resume", default=None, type=str, help="path to model weights")
     parser.add_argument(
-        "-w", "--weights", default=None, type=str,
+        "-w",
+        "--weights",
+        default=None,
+        type=str,
         help="path to weights for evaluation")
     FLAGS = parser.parse_args()
     assert FLAGS.data, "error: must provide data path"

examples/yolov3/modeling.py

@@ -73,6 +73,7 @@ class ConvBNLayer(fluid.dygraph.Layer):
             out = fluid.layers.leaky_relu(x=out, alpha=0.1)
         return out
 
+
 class YoloDetectionBlock(fluid.dygraph.Layer):
     def __init__(self, ch_in, channel):
         super(YoloDetectionBlock, self).__init__()
@@ -81,38 +82,34 @@ class YoloDetectionBlock(fluid.dygraph.Layer):
             "channel {} cannot be divided by 2".format(channel)
 
         self.conv0 = ConvBNLayer(
-            ch_in=ch_in,
-            ch_out=channel,
-            filter_size=1,
-            stride=1,
-            padding=0)
+            ch_in=ch_in, ch_out=channel, filter_size=1, stride=1, padding=0)
         self.conv1 = ConvBNLayer(
             ch_in=channel,
-            ch_out=channel*2,
+            ch_out=channel * 2,
             filter_size=3,
             stride=1,
             padding=1)
         self.conv2 = ConvBNLayer(
-            ch_in=channel*2,
+            ch_in=channel * 2,
             ch_out=channel,
             filter_size=1,
             stride=1,
             padding=0)
         self.conv3 = ConvBNLayer(
             ch_in=channel,
-            ch_out=channel*2,
+            ch_out=channel * 2,
             filter_size=3,
             stride=1,
             padding=1)
         self.route = ConvBNLayer(
-            ch_in=channel*2,
+            ch_in=channel * 2,
             ch_out=channel,
             filter_size=1,
             stride=1,
             padding=0)
         self.tip = ConvBNLayer(
             ch_in=channel,
-            ch_out=channel*2,
+            ch_out=channel * 2,
             filter_size=3,
             stride=1,
             padding=1)
@@ -149,8 +146,10 @@ class YOLOv3(Model):
             "model_mode should be 'train' 'eval' or 'test', but got " \
             "{}".format(model_mode)
         self.model_mode = str.lower(model_mode)
-        self.anchors = [10, 13, 16, 30, 33, 23, 30, 61, 62, 45,
-                        59, 119, 116, 90, 156, 198, 373, 326]
+        self.anchors = [
+            10, 13, 16, 30, 33, 23, 30, 61, 62, 45, 59, 119, 116, 90, 156, 198,
+            373, 326
+        ]
         self.anchor_masks = [[6, 7, 8], [3, 4, 5], [0, 1, 2]]
         self.valid_thresh = 0.005
         self.nms_thresh = 0.45
@@ -158,7 +157,10 @@ class YOLOv3(Model):
         self.nms_posk = 100
         self.draw_thresh = 0.5
 
-        self.backbone = darknet53(pretrained=(model_mode=='train'))
+        self.backbone = darknet53(
+            pretrained=(model_mode == 'train'),
+            with_pool=False,
+            num_classes=-1)
         self.block_outputs = []
         self.yolo_blocks = []
         self.route_blocks = []
@@ -173,32 +175,46 @@ class YOLOv3(Model):
 
             block_out = self.add_sublayer(
                 "block_out_{}".format(idx),
-                Conv2D(num_channels=1024 // (2**idx),
-                       num_filters=num_filters,
-                       filter_size=1,
-                       act=None,
-                       param_attr=ParamAttr(
-                           initializer=fluid.initializer.Normal(0., 0.02)),
-                       bias_attr=ParamAttr(
-                           initializer=fluid.initializer.Constant(0.0),
-                           regularizer=L2Decay(0.))))
+                Conv2D(
+                    num_channels=1024 // (2**idx),
+                    num_filters=num_filters,
+                    filter_size=1,
+                    act=None,
+                    param_attr=ParamAttr(
+                        initializer=fluid.initializer.Normal(0., 0.02)),
+                    bias_attr=ParamAttr(
+                        initializer=fluid.initializer.Constant(0.0),
+                        regularizer=L2Decay(0.))))
             self.block_outputs.append(block_out)
             if idx < 2:
                 route = self.add_sublayer(
                     "route2_{}".format(idx),
-                    ConvBNLayer(ch_in=512 // (2**idx),
-                                ch_out=256 // (2**idx),
-                                filter_size=1,
-                                act='leaky_relu'))
+                    ConvBNLayer(
+                        ch_in=512 // (2**idx),
+                        ch_out=256 // (2**idx),
+                        filter_size=1,
+                        act='leaky_relu'))
                 self.route_blocks.append(route)
 
+    def extract_feats(self, inputs):
+        out = self.backbone.conv0(inputs)
+        out = self.backbone.downsample0(out)
+        blocks = []
+        for i, conv_block_i in enumerate(
+                self.backbone.darknet53_conv_block_list):
+            out = conv_block_i(out)
+            blocks.append(out)
+            if i < len(self.backbone.stages) - 1:
+                out = self.backbone.downsample_list[i](out)
+        return blocks[-1:-4:-1]
+
     def forward(self, img_id, img_shape, inputs):
         outputs = []
         boxes = []
         scores = []
         downsample = 32
 
-        feats = self.backbone(inputs)
+        feats = self.extract_feats(inputs)
         route = None
         for idx, feat in enumerate(feats):
             if idx > 0:
@@ -233,15 +249,18 @@ class YOLOv3(Model):
         if self.model_mode == 'train':
             return outputs
 
-        preds = [img_id,
-                 fluid.layers.multiclass_nms(
-                    bboxes=fluid.layers.concat(boxes, axis=1),
-                    scores=fluid.layers.concat(scores, axis=2),
-                    score_threshold=self.valid_thresh,
-                    nms_top_k=self.nms_topk,
-                    keep_top_k=self.nms_posk,
-                    nms_threshold=self.nms_thresh,
-                    background_label=-1)]
+        preds = [
+            img_id, fluid.layers.multiclass_nms(
+                bboxes=fluid.layers.concat(
+                    boxes, axis=1),
+                scores=fluid.layers.concat(
+                    scores, axis=2),
+                score_threshold=self.valid_thresh,
+                nms_top_k=self.nms_topk,
+                keep_top_k=self.nms_posk,
+                nms_threshold=self.nms_thresh,
+                background_label=-1)
+        ]
 
         if self.model_mode == 'test':
             return preds
@@ -249,14 +268,17 @@ class YOLOv3(Model):
         # model_mode == "eval"
         return outputs + preds
 
+
 class YoloLoss(Loss):
     def __init__(self, num_classes=80, num_max_boxes=50):
         super(YoloLoss, self).__init__()
         self.num_classes = num_classes
         self.num_max_boxes = num_max_boxes
         self.ignore_thresh = 0.7
-        self.anchors = [10, 13, 16, 30, 33, 23, 30, 61, 62, 45,
-                        59, 119, 116, 90, 156, 198, 373, 326]
+        self.anchors = [
+            10, 13, 16, 30, 33, 23, 30, 61, 62, 45, 59, 119, 116, 90, 156, 198,
+            373, 326
+        ]
         self.anchor_masks = [[6, 7, 8], [3, 4, 5], [0, 1, 2]]
 
     def forward(self, outputs, labels):
@@ -265,7 +287,7 @@ class YoloLoss(Loss):
         losses = []
 
         for idx, out in enumerate(outputs):
-            if idx == 3: break # debug
+            if idx == 3: break  # debug
             anchor_mask = self.anchor_masks[idx]
             loss = fluid.layers.yolov3_loss(
                 x=out,
@@ -284,8 +306,10 @@ class YoloLoss(Loss):
         return losses
 
 
-def _yolov3_darknet(num_layers=53, num_classes=80,
-                    model_mode='train', pretrained=True):
+def _yolov3_darknet(num_layers=53,
+                    num_classes=80,
+                    model_mode='train',
+                    pretrained=True):
     model = YOLOv3(num_classes, model_mode)
     if pretrained:
         assert num_layers in pretrain_infos.keys(), \

examples/yolov3/transforms.py

@@ -20,6 +20,7 @@ import traceback
 import numpy as np
 
 __all__ = [
+    "Compose",
     'ColorDistort',
     'RandomExpand',
     'RandomCrop',
@@ -33,6 +34,37 @@ __all__ = [
 ]
 
 
+class Compose(object):
+    """Composes several transforms together.
+
+    Args:
+        transforms (list of ``Transform`` objects): list of transforms to compose.
+
+    """
+
+    def __init__(self, transforms):
+        self.transforms = transforms
+
+    def __call__(self, *data):
+        for f in self.transforms:
+            try:
+                data = f(*data)
+            except Exception as e:
+                stack_info = traceback.format_exc()
+                print("fail to perform transform [{}] with error: "
+                      "{} and stack:\n{}".format(f, e, str(stack_info)))
+                raise e
+        return data
+
+    def __repr__(self):
+        format_string = self.__class__.__name__ + '('
+        for t in self.transforms:
+            format_string += '\n'
+            format_string += '    {0}'.format(t)
+        format_string += '\n)'
+        return format_string
+
+
 class ColorDistort(object):
     """Random color distortion.
 
@@ -147,7 +179,10 @@ class RandomExpand(object):
         fill_value (list): color value used to fill the canvas. in RGB order.
     """
 
-    def __init__(self, ratio=4., prob=0.5, fill_value=[123.675, 116.28, 103.53]):
+    def __init__(self,
+                 ratio=4.,
+                 prob=0.5,
+                 fill_value=[123.675, 116.28, 103.53]):
         assert ratio > 1.01, "expand ratio must be larger than 1.01"
         self.ratio = ratio
         self.prob = prob
@@ -493,8 +528,7 @@ def _crop_box_with_center_constraint(box, crop):
     cropped_box[:, :2] -= crop[:2]
     cropped_box[:, 2:] -= crop[:2]
     centers = (box[:, :2] + box[:, 2:]) / 2
-    valid = np.logical_and(
-        crop[:2] <= centers, centers < crop[2:]).all(axis=1)
+    valid = np.logical_and(crop[:2] <= centers, centers < crop[2:]).all(axis=1)
     valid = np.logical_and(
         valid, (cropped_box[:, :2] < cropped_box[:, 2:]).all(axis=1))
     return cropped_box, np.where(valid)[0]
@@ -517,8 +551,8 @@ def random_crop(inputs):
         for i in range(50):
             scale = np.random.uniform(*scaling)
             min_ar, max_ar = aspect_ratios
-            ar = np.random.uniform(max(min_ar, scale**2),
-                                   min(max_ar, scale**-2))
+            ar = np.random.uniform(
+                max(min_ar, scale**2), min(max_ar, scale**-2))
             crop_h = int(h * scale / np.sqrt(ar))
             crop_w = int(w * scale * np.sqrt(ar))
             crop_y = np.random.randint(0, h - crop_h)
@@ -529,7 +563,8 @@ def random_crop(inputs):
                 continue
 
             cropped_box, valid_ids = _crop_box_with_center_constraint(
-                gt_box, np.array(crop_box, dtype=np.float32))
+                gt_box, np.array(
+                    crop_box, dtype=np.float32))
             if valid_ids.size > 0:
                 found = True
                 break
@@ -545,9 +580,7 @@ def random_crop(inputs):
 
 
 class ResizeImage(object):
-    def __init__(self,
-                 target_size=0,
-                 interp=cv2.INTER_CUBIC):
+    def __init__(self, target_size=0, interp=cv2.INTER_CUBIC):
         """
         Rescale image to the specified target size.
         If target_size is list, selected a scale randomly as the specified
@@ -574,8 +607,8 @@ class ResizeImage(object):
             raise ImageError('{}: image is not 3-dimensional.'.format(self))
         im_scale_x = float(self.target_size) / float(im.shape[1])
         im_scale_y = float(self.target_size) / float(im.shape[0])
-        resize_w = self.target_size 
-        resize_h = self.target_size 
+        resize_w = self.target_size
+        resize_h = self.target_size
 
         im = cv2.resize(
             im,
@@ -586,4 +619,3 @@ class ResizeImage(object):
             interpolation=self.interp)
 
         return [im_id, im_shape, im, gt_bbox, gt_class, gt_score]
-

hapi/callbacks.py

@@ -215,15 +215,13 @@ class ProgBarLogger(Callback):
 
         if self.train_step % self.log_freq == 0 and self.verbose and ParallelEnv(
         ).local_rank == 0:
-            # if steps is not None, last step will update in on_epoch_end
-            if self.steps and self.train_step < self.steps:
-                self._updates(logs, 'train')
-            else:
+            if self.steps is None or self.train_step < self.steps:
                 self._updates(logs, 'train')
 
     def on_epoch_end(self, epoch, logs=None):
         logs = logs or {}
-        if self.verbose and ParallelEnv().local_rank == 0:
+        if self.train_step % self.log_freq != 0 and self.verbose and ParallelEnv(
+        ).local_rank == 0:
             self._updates(logs, 'train')
 
     def on_eval_begin(self, logs=None):
@@ -238,20 +236,20 @@ class ProgBarLogger(Callback):
 
     def on_eval_batch_end(self, step, logs=None):
         logs = logs or {}
-        self.eval_step = step
+        self.eval_step += 1
         samples = logs.get('batch_size', 1)
         self.evaled_samples += samples
 
         if self.eval_step % self.log_freq == 0 and self.verbose and ParallelEnv(
         ).local_rank == 0:
-            # if steps is not None, last step will update in on_epoch_end
-            if self.eval_steps and self.eval_step < self.eval_steps:
+            if self.eval_steps is None or self.eval_step < self.eval_steps:
                 self._updates(logs, 'eval')
 
     def on_eval_end(self, logs=None):
         logs = logs or {}
         if self.verbose and ParallelEnv().local_rank == 0:
-            self._updates(logs, 'eval')
+            if self.eval_step % self.log_freq != 0:
+                self._updates(logs, 'eval')
             print('Eval samples: %d' % (self.evaled_samples))
 
 

hapi/datasets/folder.py

@@ -18,7 +18,7 @@ import cv2
 
 from paddle.io import Dataset
 
-__all__ = ["DatasetFolder"]
+__all__ = ["DatasetFolder", "ImageFolder"]
 
 
 def has_valid_extension(filename, extensions):
@@ -150,7 +150,7 @@ class DatasetFolder(Dataset):
         path, target = self.samples[index]
         sample = self.loader(path)
         if self.transform is not None:
-            sample, target = self.transform(sample, target)
+            sample, target = self.transform(sample)
 
         return sample, target
 
@@ -164,3 +164,80 @@ IMG_EXTENSIONS = ('.jpg', '.jpeg', '.png', '.ppm', '.bmp', '.pgm', '.tif',
 
 def cv2_loader(path):
     return cv2.imread(path)
+
+
+class ImageFolder(Dataset):
+    """A generic data loader where the samples are arranged in this way:
+
+        root/1.ext
+        root/2.ext
+        root/sub_dir/3.ext
+
+    Args:
+        root (string): Root directory path.
+        loader (callable, optional): A function to load a sample given its path.
+        extensions (tuple[string], optional): A list of allowed extensions.
+            both extensions and is_valid_file should not be passed.
+        transform (callable, optional): A function/transform that takes in
+            a sample and returns a transformed version.
+        is_valid_file (callable, optional): A function that takes path of a file
+            and check if the file is a valid file (used to check of corrupt files)
+            both extensions and is_valid_file should not be passed.
+
+     Attributes:
+        samples (list): List of sample path
+     """
+
+    def __init__(self,
+                 root,
+                 loader=None,
+                 extensions=None,
+                 transform=None,
+                 is_valid_file=None):
+        self.root = root
+        if extensions is None:
+            extensions = IMG_EXTENSIONS
+
+        samples = []
+        path = os.path.expanduser(root)
+        if not ((extensions is None) ^ (is_valid_file is None)):
+            raise ValueError(
+                "Both extensions and is_valid_file cannot be None or not None at the same time"
+            )
+        if extensions is not None:
+
+            def is_valid_file(x):
+                return has_valid_extension(x, extensions)
+
+        for root, _, fnames in sorted(os.walk(path, followlinks=True)):
+            for fname in sorted(fnames):
+                f = os.path.join(root, fname)
+                if is_valid_file(f):
+                    samples.append(f)
+
+        if len(samples) == 0:
+            raise (RuntimeError(
+                "Found 0 files in subfolders of: " + self.root + "\n"
+                "Supported extensions are: " + ",".join(extensions)))
+
+        self.loader = cv2_loader if loader is None else loader
+        self.extensions = extensions
+        self.samples = samples
+        self.transform = transform
+
+    def __getitem__(self, index):
+        """
+        Args:
+            index (int): Index
+
+        Returns:
+            tuple: (sample, target) where target is class_index of the target class.
+        """
+        path = self.samples[index]
+        sample = self.loader(path)
+        if self.transform is not None:
+            sample = self.transform(sample)
+        return [sample]
+
+    def __len__(self):
+        return len(self.samples)

hapi/model.py

@@ -576,14 +576,15 @@ class DynamicGraphAdapter(object):
         if labels is not None:
             labels = [to_variable(l) for l in to_list(labels)]
         if self._nranks > 1:
-            outputs = self.ddp_model.forward(*[to_variable(x) for x in inputs])
+            outputs = self.ddp_model.forward(
+                * [to_variable(x) for x in inputs])
             losses = self.model._loss_function(outputs, labels)
             final_loss = fluid.layers.sum(losses)
             final_loss = self.ddp_model.scale_loss(final_loss)
             final_loss.backward()
             self.ddp_model.apply_collective_grads()
         else:
-            outputs = self.model.forward(*[to_variable(x) for x in inputs])
+            outputs = self.model.forward(* [to_variable(x) for x in inputs])
             losses = self.model._loss_function(outputs, labels)
             final_loss = fluid.layers.sum(losses)
             final_loss.backward()
@@ -592,9 +593,9 @@ class DynamicGraphAdapter(object):
         self.model.clear_gradients()
         metrics = []
         for metric in self.model._metrics:
-            metric_outs = metric.add_metric_op(
-                *(to_list(outputs) + to_list(labels)))
-            m = metric.update(*[to_numpy(m) for m in to_list(metric_outs)])
+            metric_outs = metric.add_metric_op(*(to_list(outputs) + to_list(
+                labels)))
+            m = metric.update(* [to_numpy(m) for m in to_list(metric_outs)])
             metrics.append(m)
 
         return ([to_numpy(l) for l in losses], metrics) \
@@ -606,7 +607,7 @@ class DynamicGraphAdapter(object):
         inputs = to_list(inputs)
         if labels is not None:
             labels = [to_variable(l) for l in to_list(labels)]
-        outputs = self.model.forward(*[to_variable(x) for x in inputs])
+        outputs = self.model.forward(* [to_variable(x) for x in inputs])
         if self.model._loss_function:
             losses = self.model._loss_function(outputs, labels)
         else:
@@ -632,9 +633,9 @@ class DynamicGraphAdapter(object):
                     self._merge_count[self.mode + '_total'] += samples
                     self._merge_count[self.mode + '_batch'] = samples
 
-            metric_outs = metric.add_metric_op(
-                *(to_list(outputs) + to_list(labels)))
-            m = metric.update(*[to_numpy(m) for m in to_list(metric_outs)])
+            metric_outs = metric.add_metric_op(*(to_list(outputs) + to_list(
+                labels)))
+            m = metric.update(* [to_numpy(m) for m in to_list(metric_outs)])
             metrics.append(m)
 
         # To be consistent with static graph
@@ -1009,7 +1010,7 @@ class Model(fluid.dygraph.Layer):
         do_eval = eval_loader is not None
         self._test_dataloader = eval_loader
         metrics_name = self._metrics_name()
-        steps = len(train_loader) if hasattr(train_loader, '__len__') else None
+        steps = self._len_data_loader(train_loader)
         cbks = config_callbacks(
             callbacks,
             model=self,
@@ -1037,8 +1038,7 @@ class Model(fluid.dygraph.Layer):
                 if not isinstance(eval_loader, Iterable):
                     loader = eval_loader()
 
-                eval_steps = len(loader) if hasattr(loader,
-                                                    '__len__') else None
+                eval_steps = self._len_data_loader(loader)
                 cbks.on_begin('eval', {
                     'steps': eval_steps,
                     'metrics_name': metrics_name
@@ -1114,7 +1114,7 @@ class Model(fluid.dygraph.Layer):
         if not isinstance(eval_loader, Iterable):
             loader = eval_loader()
 
-        eval_steps = len(loader) if hasattr(loader, '__len__') else None
+        eval_steps = self._len_data_loader(loader)
         cbks.on_begin('eval',
                       {'steps': eval_steps,
                        'metrics_name': metrics_name})
@@ -1135,7 +1135,7 @@ class Model(fluid.dygraph.Layer):
                 test_data,
                 batch_size=1,
                 num_workers=0,
-                stack_outputs=True):
+                stack_outputs=False):
         """
         FIXME: add more comments and usage
         Args:
@@ -1161,7 +1161,7 @@ class Model(fluid.dygraph.Layer):
         if fluid.in_dygraph_mode():
             feed_list = None
         else:
-            feed_list = [x.forward() for x in self._inputs + self._labels]
+            feed_list = [x.forward() for x in self._inputs]
 
         if test_data is not None and isinstance(test_data, Dataset):
             test_sampler = DistributedBatchSampler(
@@ -1183,20 +1183,29 @@ class Model(fluid.dygraph.Layer):
             loader = test_loader()
 
         outputs = []
+        count = 0
         for data in tqdm.tqdm(loader):
             data = flatten(data)
-            outputs.append(self.test_batch(data[:len(self._inputs)]))
+            out = to_list(self.test_batch(data[:len(self._inputs)]))
+            outputs.append(out)
+            count += out[0].shape[0]
+
+        if test_loader is not None and self._adapter._nranks > 1 \
+                    and isinstance(test_loader, DataLoader) \
+                    and count > len(test_loader.dataset):
+            size = outputs[-1][0].shape[0] - (count - len(test_loader.dataset))
+            outputs[-1] = [o[:size] for o in outputs[-1]]
 
         # NOTE: for lod tensor output, we should not stack outputs
         # for stacking may loss its detail info
+
         outputs = list(zip(*outputs))
+
         if stack_outputs:
-            outputs = [np.stack(outs, axis=0) for outs in outputs]
+            outputs = [np.vstack(outs) for outs in outputs]
 
         self._test_dataloader = None
-        if test_loader is not None and self._adapter._nranks > 1 \
-                    and isinstance(test_loader, DataLoader):
-            outputs = [o[:len(test_loader.dataset)] for o in outputs]
+
         return outputs
 
     def _run_one_epoch(self,
@@ -1205,7 +1214,7 @@ class Model(fluid.dygraph.Layer):
                        mode,
                        metrics_name,
                        epoch=None):
-        size = len(data_loader) if hasattr(data_loader, '__len__') else None
+        size = self._len_data_loader(data_loader)
         logs = {
             'steps': size,
             'metrics_name': metrics_name,
@@ -1236,10 +1245,10 @@ class Model(fluid.dygraph.Layer):
             callbacks.on_batch_begin(mode, step, logs)
             if mode == 'train':
                 outs = self.train_batch(data[:len(self._inputs)],
-                                           data[len(self._inputs):])
+                                        data[len(self._inputs):])
             else:
                 outs = self.eval_batch(data[:len(self._inputs)],
-                                          data[len(self._inputs):])
+                                       data[len(self._inputs):])
 
             # losses
             loss = outs[0] if self._metrics else outs
@@ -1267,7 +1276,7 @@ class Model(fluid.dygraph.Layer):
 
         if mode == 'train':
             assert epoch is not None, 'when mode is train, epoch must be given'
-            callbacks.on_epoch_end(epoch)
+            callbacks.on_epoch_end(epoch, logs)
 
         return logs
 
@@ -1280,3 +1289,10 @@ class Model(fluid.dygraph.Layer):
         for m in self._metrics:
             metrics_name.extend(to_list(m.name()))
         return metrics_name
+
+    def _len_data_loader(self, data_loader):
+        try:
+            steps = len(data_loader)
+        except Exception:
+            steps = None
+        return steps

hapi/text/bert/optimization.py

@@ -130,6 +130,18 @@ class Optimizer(object):
                 return True
         return False
 
+    def state_dict(self):
+        return self.optimizer.state_dict()
+
+    def set_dict(self, state_dict):
+        return self.optimizer.set_dict(state_dict)
+
+    def get_opti_var_name_list(self):
+        return self.optimizer.get_opti_var_name_list()
+
+    def current_step_lr(self):
+        return self.optimizer.current_step_lr()
+
     def minimize(self, loss, use_data_parallel=False, model=None):
         param_list = dict()
 

hapi/text/text.py

@@ -49,7 +49,7 @@ __all__ = [
     'BeamSearchDecoder', 'MultiHeadAttention', 'FFN',
     'TransformerEncoderLayer', 'TransformerEncoder', 'TransformerDecoderLayer',
     'TransformerDecoder', 'TransformerBeamSearchDecoder', 'Linear_chain_crf',
-    'Crf_decoding', 'SequenceTagging'
+    'Crf_decoding', 'SequenceTagging', 'GRUEncoderLayer'
 ]
 
 
@@ -238,8 +238,9 @@ class BasicLSTMCell(RNNCell):
         self._bias_attr = bias_attr
         self._gate_activation = gate_activation or layers.sigmoid
         self._activation = activation or layers.tanh
-        self._forget_bias = layers.fill_constant(
-            [1], dtype=dtype, value=forget_bias)
+        # TODO(guosheng): find better way to resolve constants in __init__
+        self._forget_bias = layers.create_global_var(
+            shape=[1], dtype=dtype, value=forget_bias, persistable=True)
         self._forget_bias.stop_gradient = False
         self._dtype = dtype
         self._input_size = input_size
@@ -762,7 +763,7 @@ class BasicGRUCell(RNNCell):
         c = self._activation(candidate)
         new_hidden = u * pre_hidden + (1 - u) * c
 
-        return new_hidden
+        return new_hidden, new_hidden
 
     @property
     def state_shape(self):
@@ -817,7 +818,7 @@ class RNN(fluid.dygraph.Layer):
                     lambda x: fluid.layers.transpose(x, [1, 0] + list(
                         range(2, len(x.shape)))), inputs)
 
-            if sequence_length:
+            if sequence_length is not None:
                 mask = fluid.layers.sequence_mask(
                     sequence_length,
                     maxlen=time_steps,
@@ -828,7 +829,7 @@ class RNN(fluid.dygraph.Layer):
                 inputs = map_structure(
                     lambda x: fluid.layers.reverse(x, axis=[0]), inputs)
                 mask = fluid.layers.reverse(
-                    mask, axis=[0]) if sequence_length else None
+                    mask, axis=[0]) if sequence_length is not None else None
 
             states = initial_states
             outputs = []
@@ -836,7 +837,7 @@ class RNN(fluid.dygraph.Layer):
                 step_inputs = map_structure(lambda x: x[i], inputs)
                 step_outputs, new_states = self.cell(step_inputs, states,
                                                      **kwargs)
-                if sequence_length:
+                if sequence_length is not None:
                     new_states = map_structure(
                         partial(
                             _maybe_copy, step_mask=mask[i]),
@@ -1740,6 +1741,64 @@ class Crf_decoding(fluid.dygraph.Layer):
         return viterbi_path
 
 
+class GRUEncoderLayer(Layer):
+    def __init__(self,
+                 input_dim,
+                 grnn_hidden_dim,
+                 init_bound,
+                 num_layers=1,
+                 h_0=None,
+                 is_bidirection=False):
+        super(GRUEncoderLayer, self).__init__()
+        self.h_0 = h_0
+        self.num_layers = num_layers
+        self.is_bidirection = is_bidirection
+        self.gru_list = []
+        self.gru_r_list = []
+        for i in range(num_layers):
+            self.basic_gru_cell = BasicGRUCell(
+                input_size=input_dim if i == 0 else input_dim * 2,
+                hidden_size=grnn_hidden_dim,
+                param_attr=fluid.ParamAttr(
+                    initializer=fluid.initializer.UniformInitializer(
+                        low=-init_bound, high=init_bound),
+                    regularizer=fluid.regularizer.L2DecayRegularizer(
+                        regularization_coeff=1e-4)))
+            self.gru_list.append(
+                self.add_sublayer(
+                    "gru_%d" % i,
+                    RNN(self.basic_gru_cell,
+                        is_reverse=False,
+                        time_major=False)))
+        if self.is_bidirection:
+            for i in range(num_layers):
+                self.basic_gru_cell_r = BasicGRUCell(
+                    input_size=input_dim if i == 0 else input_dim * 2,
+                    hidden_size=grnn_hidden_dim,
+                    param_attr=fluid.ParamAttr(
+                        initializer=fluid.initializer.UniformInitializer(
+                            low=-init_bound, high=init_bound),
+                        regularizer=fluid.regularizer.L2DecayRegularizer(
+                            regularization_coeff=1e-4)))
+                self.gru_r_list.append(
+                    self.add_sublayer(
+                        "gru_r_%d" % i,
+                        RNN(self.basic_gru_cell_r,
+                            is_reverse=True,
+                            time_major=False)))
+
+    def forward(self, input_feature):
+        for i in range(self.num_layers):
+            pre_gru, pre_state = self.gru_list[i](input_feature)
+            if self.is_bidirection:
+                gru_r, r_state = self.gru_r_list[i](input_feature)
+                out = fluid.layers.concat(input=[pre_gru, gru_r], axis=-1)
+            else:
+                out = pre_gru
+            input_feature = out
+        return out
+
+
 class SequenceTagging(fluid.dygraph.Layer):
     def __init__(self,
                  vocab_size,
@@ -1789,26 +1848,13 @@ class SequenceTagging(fluid.dygraph.Layer):
             force_cpu=True,
             name='h_0')
 
-        self.bigru_units = []
-        for i in range(self.bigru_num):
-            if i == 0:
-                self.bigru_units.append(
-                    self.add_sublayer(
-                        "bigru_units%d" % i,
-                        BiGRU(
-                            self.grnn_hidden_dim,
-                            self.grnn_hidden_dim,
-                            self.init_bound,
-                            h_0=h_0)))
-            else:
-                self.bigru_units.append(
-                    self.add_sublayer(
-                        "bigru_units%d" % i,
-                        BiGRU(
-                            self.grnn_hidden_dim * 2,
-                            self.grnn_hidden_dim,
-                            self.init_bound,
-                            h_0=h_0)))
+        self.gru_encoder = GRUEncoderLayer(
+            input_dim=self.grnn_hidden_dim,
+            grnn_hidden_dim=self.grnn_hidden_dim,
+            init_bound=self.init_bound,
+            num_layers=self.bigru_num,
+            h_0=h_0,
+            is_bidirection=True)
 
         self.fc = Linear(
             input_dim=self.grnn_hidden_dim * 2,
@@ -1836,10 +1882,7 @@ class SequenceTagging(fluid.dygraph.Layer):
         word_embed = self.word_embedding(word)
         input_feature = word_embed
 
-        for i in range(self.bigru_num):
-            bigru_output = self.bigru_units[i](input_feature)
-            input_feature = bigru_output
-
+        bigru_output = self.gru_encoder(input_feature)
         emission = self.fc(bigru_output)
 
         if target is not None:

hapi/vision/models/darknet.py

@@ -12,11 +12,12 @@
 #See the License for the specific language governing permissions and
 #limitations under the License.
 
+import math
 import paddle.fluid as fluid
 from paddle.fluid.param_attr import ParamAttr
 from paddle.fluid.regularizer import L2Decay
 
-from paddle.fluid.dygraph.nn import Conv2D, BatchNorm
+from paddle.fluid.dygraph.nn import Conv2D, BatchNorm, Pool2D, Linear
 
 from hapi.model import Model
 from hapi.download import get_weights_path
@@ -25,8 +26,8 @@ __all__ = ['DarkNet', 'darknet53']
 
 # {num_layers: (url, md5)}
 pretrain_infos = {
-        53: ('https://paddlemodels.bj.bcebos.com/hapi/darknet53.pdparams',
-            '2506357a5c31e865785112fc614a487d')
+    53: ('https://paddle-hapi.bj.bcebos.com/models/darknet53.pdparams',
+         'ca506a90e2efecb9a2093f8ada808708')
 }
 
 
@@ -66,17 +67,14 @@ class ConvBNLayer(fluid.dygraph.Layer):
     def forward(self, inputs):
         out = self.conv(inputs)
         out = self.batch_norm(out)
+        # out = fluid.layers.relu(out)
         if self.act == 'leaky':
             out = fluid.layers.leaky_relu(x=out, alpha=0.1)
         return out
 
+
 class DownSample(fluid.dygraph.Layer):
-    def __init__(self,
-                 ch_in,
-                 ch_out,
-                 filter_size=3,
-                 stride=2,
-                 padding=1):
+    def __init__(self, ch_in, ch_out, filter_size=3, stride=2, padding=1):
 
         super(DownSample, self).__init__()
 
@@ -87,46 +85,45 @@ class DownSample(fluid.dygraph.Layer):
             stride=stride,
             padding=padding)
         self.ch_out = ch_out
+
     def forward(self, inputs):
         out = self.conv_bn_layer(inputs)
         return out
 
+
 class BasicBlock(fluid.dygraph.Layer):
     def __init__(self, ch_in, ch_out):
         super(BasicBlock, self).__init__()
 
         self.conv1 = ConvBNLayer(
-            ch_in=ch_in,
-            ch_out=ch_out,
-            filter_size=1,
-            stride=1,
-            padding=0)
+            ch_in=ch_in, ch_out=ch_out, filter_size=1, stride=1, padding=0)
         self.conv2 = ConvBNLayer(
             ch_in=ch_out,
-            ch_out=ch_out*2,
+            ch_out=ch_out * 2,
             filter_size=3,
             stride=1,
             padding=1)
+
     def forward(self, inputs):
         conv1 = self.conv1(inputs)
         conv2 = self.conv2(conv1)
         out = fluid.layers.elementwise_add(x=inputs, y=conv2, act=None)
         return out
 
+
 class LayerWarp(fluid.dygraph.Layer):
     def __init__(self, ch_in, ch_out, count):
-        super(LayerWarp,self).__init__()
+        super(LayerWarp, self).__init__()
 
         self.basicblock0 = BasicBlock(ch_in, ch_out)
         self.res_out_list = []
-        for i in range(1,count):
+        for i in range(1, count):
             res_out = self.add_sublayer("basic_block_%d" % (i),
-                BasicBlock(
-                    ch_out*2,
-                    ch_out))
+                                        BasicBlock(ch_out * 2, ch_out))
             self.res_out_list.append(res_out)
         self.ch_out = ch_out
-    def forward(self,inputs):
+
+    def forward(self, inputs):
         y = self.basicblock0(inputs)
         for basic_block_i in self.res_out_list:
             y = basic_block_i(y)
@@ -142,61 +139,82 @@ class DarkNet(Model):
 
     Args:
         num_layers (int): layer number of DarkNet, only 53 supported currently, default: 53.
-        ch_in (int): channel number of input data, default 3.
+        num_classes (int): output dim of last fc layer. If num_classes <=0, last fc layer 
+                            will not be defined. Default: 1000.
+        with_pool (bool): use pool before the last fc layer or not. Default: True.
+        classifier_activation (str): activation for the last fc layer. Default: 'softmax'.
     """
 
-    def __init__(self, num_layers=53, ch_in=3):
+    def __init__(self,
+                 num_layers=53,
+                 num_classes=1000,
+                 with_pool=True,
+                 classifier_activation='softmax'):
         super(DarkNet, self).__init__()
         assert num_layers in DarkNet_cfg.keys(), \
             "only support num_layers in {} currently" \
             .format(DarkNet_cfg.keys())
         self.stages = DarkNet_cfg[num_layers]
         self.stages = self.stages[0:5]
-
+        self.num_classes = num_classes
+        self.with_pool = True
+        ch_in = 3
         self.conv0 = ConvBNLayer(
-            ch_in=ch_in,
-            ch_out=32,
-            filter_size=3,
-            stride=1,
-            padding=1)
+            ch_in=ch_in, ch_out=32, filter_size=3, stride=1, padding=1)
 
-        self.downsample0 = DownSample(
-            ch_in=32,
-            ch_out=32 * 2)
+        self.downsample0 = DownSample(ch_in=32, ch_out=32 * 2)
         self.darknet53_conv_block_list = []
         self.downsample_list = []
-        ch_in = [64,128,256,512,1024]
+        ch_in = [64, 128, 256, 512, 1024]
         for i, stage in enumerate(self.stages):
-            conv_block = self.add_sublayer(
-                "stage_%d" % (i),
-                LayerWarp(
-                int(ch_in[i]),
-                32*(2**i),
-                stage))
+            conv_block = self.add_sublayer("stage_%d" % (i),
+                                           LayerWarp(
+                                               int(ch_in[i]), 32 * (2**i),
+                                               stage))
             self.darknet53_conv_block_list.append(conv_block)
+
         for i in range(len(self.stages) - 1):
             downsample = self.add_sublayer(
                 "stage_%d_downsample" % i,
                 DownSample(
-                    ch_in = 32*(2**(i+1)),
-                    ch_out = 32*(2**(i+2))))
+                    ch_in=32 * (2**(i + 1)), ch_out=32 * (2**(i + 2))))
             self.downsample_list.append(downsample)
 
-    def forward(self,inputs):
-        
+        if self.with_pool:
+            self.global_pool = Pool2D(
+                pool_size=7, pool_type='avg', global_pooling=True)
+
+        if self.num_classes > 0:
+            stdv = 1.0 / math.sqrt(32 * (2**(i + 2)))
+            self.fc_input_dim = 32 * (2**(i + 2))
+
+            self.fc = Linear(
+                self.fc_input_dim,
+                num_classes,
+                act='softmax',
+                param_attr=fluid.param_attr.ParamAttr(
+                    initializer=fluid.initializer.Uniform(-stdv, stdv)))
+
+    def forward(self, inputs):
+
         out = self.conv0(inputs)
         out = self.downsample0(out)
-        blocks = []
+
         for i, conv_block_i in enumerate(self.darknet53_conv_block_list):
             out = conv_block_i(out)
-            blocks.append(out)
             if i < len(self.stages) - 1:
                 out = self.downsample_list[i](out)
-        return blocks[-1:-4:-1]
+
+        if self.with_pool:
+            out = self.global_pool(out)
+        if self.num_classes > 0:
+            out = fluid.layers.reshape(out, shape=[-1, self.fc_input_dim])
+            out = self.fc(out)
+        return out
 
 
-def _darknet(num_layers=53, input_channels=3, pretrained=True):
-    model = DarkNet(num_layers, input_channels)
+def _darknet(num_layers=53, pretrained=False, **kwargs):
+    model = DarkNet(num_layers, **kwargs)
     if pretrained:
         assert num_layers in pretrain_infos.keys(), \
                 "DarkNet{} do not have pretrained weights now, " \
@@ -208,7 +226,7 @@ def _darknet(num_layers=53, input_channels=3, pretrained=True):
     return model
 
 
-def darknet53(input_channels=3, pretrained=True):
+def darknet53(pretrained=False, **kwargs):
     """DarkNet 53-layer model
     
     Args:
@@ -216,4 +234,4 @@ def darknet53(input_channels=3, pretrained=True):
         pretrained (bool): If True, returns a model pre-trained on ImageNet,
             default True.
     """
-    return _darknet(53, input_channels, pretrained)
+    return _darknet(53, pretrained, **kwargs)

hapi/vision/models/lenet.py

+#  Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+#Licensed under the Apache License, Version 2.0 (the "License");
+#you may not use this file except in compliance with the License.
+#You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+#Unless required by applicable law or agreed to in writing, software
+#distributed under the License is distributed on an "AS IS" BASIS,
+#WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#See the License for the specific language governing permissions and
+#limitations under the License.
+
+import paddle.fluid as fluid
+
+from paddle.fluid.dygraph.nn import Conv2D, BatchNorm, Pool2D, Linear
+from paddle.fluid.dygraph.container import Sequential
+from hapi.model import Model
+
+__all__ = ['LeNet']
+
+
+class LeNet(Model):
+    """LeNet model from
+    `"LeCun Y, Bottou L, Bengio Y, et al. Gradient-based learning applied to document recognition[J]. Proceedings of the IEEE, 1998, 86(11): 2278-2324.`_
+
+    Args:
+        num_classes (int): output dim of last fc layer. If num_classes <=0, last fc layer 
+                            will not be defined. Default: 10.
+        classifier_activation (str): activation for the last fc layer. Default: 'softmax'.
+    """
+
+    def __init__(self, num_classes=10, classifier_activation='softmax'):
+        super(LeNet, self).__init__()
+        self.num_classes = num_classes
+        self.features = Sequential(
+            Conv2D(
+                1, 6, 3, stride=1, padding=1),
+            Pool2D(2, 'max', 2),
+            Conv2D(
+                6, 16, 5, stride=1, padding=0),
+            Pool2D(2, 'max', 2))
+
+        if num_classes > 0:
+            self.fc = Sequential(
+                Linear(400, 120),
+                Linear(120, 84),
+                Linear(
+                    84, 10, act=classifier_activation))
+
+    def forward(self, inputs):
+        x = self.features(inputs)
+
+        if self.num_classes > 0:
+            x = fluid.layers.flatten(x, 1)
+            x = self.fc(x)
+        return x

hapi/vision/transforms/transforms.py

@@ -64,10 +64,10 @@ class Compose(object):
     def __init__(self, transforms):
         self.transforms = transforms
 
-    def __call__(self, *data):
+    def __call__(self, data):
         for f in self.transforms:
             try:
-                data = f(*data)
+                data = f(data)
             except Exception as e:
                 stack_info = traceback.format_exc()
                 print("fail to perform transform [{}] with error: "
@@ -130,8 +130,8 @@ class Resize(object):
         self.size = size
         self.interpolation = interpolation
 
-    def __call__(self, img, lbl):
-        return F.resize(img, self.size, self.interpolation), lbl
+    def __call__(self, img):
+        return F.resize(img, self.size, self.interpolation)
 
 
 class RandomResizedCrop(object):
@@ -193,10 +193,10 @@ class RandomResizedCrop(object):
         y = (height - h) // 2
         return x, y, w, h
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         x, y, w, h = self._get_params(img)
         cropped_img = img[y:y + h, x:x + w]
-        return F.resize(cropped_img, self.output_size, self.interpolation), lbl
+        return F.resize(cropped_img, self.output_size, self.interpolation)
 
 
 class CenterCropResize(object):
@@ -224,10 +224,10 @@ class CenterCropResize(object):
         y = (w + 1 - c) // 2
         return c, x, y
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         c, x, y = self._get_params(img)
         cropped_img = img[x:x + c, y:y + c, :]
-        return F.resize(cropped_img, self.size, self.interpolation), lbl
+        return F.resize(cropped_img, self.size, self.interpolation)
 
 
 class CenterCrop(object):
@@ -251,10 +251,10 @@ class CenterCrop(object):
         y = int(round((h - th) / 2.0))
         return x, y
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         x, y = self._get_params(img)
         th, tw = self.output_size
-        return img[y:y + th, x:x + tw], lbl
+        return img[y:y + th, x:x + tw]
 
 
 class RandomHorizontalFlip(object):
@@ -267,10 +267,10 @@ class RandomHorizontalFlip(object):
     def __init__(self, prob=0.5):
         self.prob = prob
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         if np.random.random() < self.prob:
-            return F.flip(img, code=1), lbl
-        return img, lbl
+            return F.flip(img, code=1)
+        return img
 
 
 class RandomVerticalFlip(object):
@@ -283,10 +283,10 @@ class RandomVerticalFlip(object):
     def __init__(self, prob=0.5):
         self.prob = prob
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         if np.random.random() < self.prob:
-            return F.flip(img, code=0), lbl
-        return img, lbl
+            return F.flip(img, code=0)
+        return img
 
 
 class Normalize(object):
@@ -311,8 +311,8 @@ class Normalize(object):
         self.mean = np.array(mean, dtype=np.float32).reshape(len(mean), 1, 1)
         self.std = np.array(std, dtype=np.float32).reshape(len(std), 1, 1)
 
-    def __call__(self, img, lbl):
-        return (img - self.mean) / self.std, lbl
+    def __call__(self, img):
+        return (img - self.mean) / self.std
 
 
 class Permute(object):
@@ -333,12 +333,12 @@ class Permute(object):
         self.mode = mode
         self.to_rgb = to_rgb
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         if self.to_rgb:
             img = img[..., ::-1]
         if self.mode == "CHW":
-            return img.transpose((2, 0, 1)), lbl
-        return img, lbl
+            return img.transpose((2, 0, 1))
+        return img
 
 
 class GaussianNoise(object):
@@ -354,11 +354,11 @@ class GaussianNoise(object):
         self.mean = np.array(mean, dtype=np.float32)
         self.std = np.array(std, dtype=np.float32)
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         dtype = img.dtype
         noise = np.random.normal(self.mean, self.std, img.shape) * 255
         img = img + noise.astype(np.float32)
-        return np.clip(img, 0, 255).astype(dtype), lbl
+        return np.clip(img, 0, 255).astype(dtype)
 
 
 class BrightnessTransform(object):
@@ -374,15 +374,15 @@ class BrightnessTransform(object):
             raise ValueError("brightness value should be non-negative")
         self.value = value
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         if self.value == 0:
-            return img, lbl
+            return img
 
         dtype = img.dtype
         img = img.astype(np.float32)
         alpha = np.random.uniform(max(0, 1 - self.value), 1 + self.value)
         img = img * alpha
-        return img.clip(0, 255).astype(dtype), lbl
+        return img.clip(0, 255).astype(dtype)
 
 
 class ContrastTransform(object):
@@ -398,16 +398,16 @@ class ContrastTransform(object):
             raise ValueError("contrast value should be non-negative")
         self.value = value
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         if self.value == 0:
-            return img, lbl
+            return img
 
         dtype = img.dtype
         img = img.astype(np.float32)
         alpha = np.random.uniform(max(0, 1 - self.value), 1 + self.value)
         img = img * alpha + cv2.cvtColor(img, cv2.COLOR_BGR2GRAY).mean() * (
             1 - alpha)
-        return img.clip(0, 255).astype(dtype), lbl
+        return img.clip(0, 255).astype(dtype)
 
 
 class SaturationTransform(object):
@@ -423,9 +423,9 @@ class SaturationTransform(object):
             raise ValueError("saturation value should be non-negative")
         self.value = value
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         if self.value == 0:
-            return img, lbl
+            return img
 
         dtype = img.dtype
         img = img.astype(np.float32)
@@ -433,7 +433,7 @@ class SaturationTransform(object):
         gray_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
         gray_img = gray_img[..., np.newaxis]
         img = img * alpha + gray_img * (1 - alpha)
-        return img.clip(0, 255).astype(dtype), lbl
+        return img.clip(0, 255).astype(dtype)
 
 
 class HueTransform(object):
@@ -449,9 +449,9 @@ class HueTransform(object):
             raise ValueError("hue value should be in [0.0, 0.5]")
         self.value = value
 
-    def __call__(self, img, lbl):
+    def __call__(self, img):
         if self.value == 0:
-            return img, lbl
+            return img
 
         dtype = img.dtype
         img = img.astype(np.uint8)
@@ -464,7 +464,7 @@ class HueTransform(object):
         with np.errstate(over="ignore"):
             h += np.uint8(alpha * 255)
         hsv_img = cv2.merge([h, s, v])
-        return cv2.cvtColor(hsv_img, cv2.COLOR_HSV2BGR_FULL).astype(dtype), lbl
+        return cv2.cvtColor(hsv_img, cv2.COLOR_HSV2BGR_FULL).astype(dtype)
 
 
 class ColorJitter(object):
@@ -499,5 +499,5 @@ class ColorJitter(object):
         random.shuffle(transforms)
         self.transforms = Compose(transforms)
 
-    def __call__(self, img, lbl):
-        return self.transforms(img, lbl)
+    def __call__(self, img):
+        return self.transforms(img)

mnist.py

@@ -24,10 +24,10 @@ import numpy as np
 from paddle import fluid
 from paddle.fluid.optimizer import Momentum
 from paddle.fluid.dygraph.nn import Conv2D, Pool2D, Linear
-from vision.datasets import MNIST as MnistDataset
+from hapi.datasets.mnist import MNIST as MnistDataset
 
-from model import Model, CrossEntropy, Input, set_device
-from metrics import Accuracy
+from hapi.model import Model, CrossEntropy, Input, set_device
+from hapi.metrics import Accuracy
 
 
 class SimpleImgConvPool(fluid.dygraph.Layer):

tests/test_model.py

@@ -190,7 +190,8 @@ class TestModel(unittest.TestCase):
 
         eval_result = model.evaluate(val_dataset, batch_size=batch_size)
 
-        output = model.predict(test_dataset, batch_size=batch_size)
+        output = model.predict(
+            test_dataset, batch_size=batch_size, stack_outputs=True)
 
         np.testing.assert_equal(output[0].shape[0], len(test_dataset))