Add imikolov.py and unittest for book chapter word2vec

python/paddle/v2/dataset/imikolov.py

+"""
+imikolov's simple dataset: http://www.fit.vutbr.cz/~imikolov/rnnlm/
+"""
+import paddle.v2.dataset.common
+import tarfile
+import collections
+
+__all__ = ['train', 'test']
+
+URL = 'http://www.fit.vutbr.cz/~imikolov/rnnlm/simple-examples.tgz'
+MD5 = '30177ea32e27c525793142b6bf2c8e2d'
+
+
+def add(a_dict, ele):
+    if ele in a_dict:
+        a_dict[ele] += 1
+    else:
+        a_dict[ele] = 1
+
+
+def word_count(f, word_freq=None):
+    if word_freq == None:
+        word_freq = {}
+
+    for l in f:
+        for w in l.strip().split():
+            add(word_freq, w)
+        add(word_freq, '<s>')
+        add(word_freq, '<e>')
+
+    return word_freq
+
+
+def build_dict(train_filename, test_filename):
+    with tarfile.open(
+            paddle.v2.dataset.common.download(
+                paddle.v2.dataset.imikolov.URL, 'imikolov',
+                paddle.v2.dataset.imikolov.MD5)) as tf:
+        trainf = tf.extractfile(train_filename)
+        testf = tf.extractfile(test_filename)
+        word_freq = word_count(testf, word_count(trainf))
+
+        STOPWORD_FREQ = 3000
+        TYPO_FREQ = 50
+        word_freq = filter(lambda x: x[1] > TYPO_FREQ and x[1] < STOPWORD_FREQ,
+                           word_freq.items())
+
+        dictionary = sorted(word_freq, key=lambda x: (-x[1], x[0]))
+        words, _ = list(zip(*dictionary))
+        word_idx = dict(zip(words, xrange(len(words))))
+        word_idx['<any>'] = len(words)
+
+    return word_idx
+
+
+word_idx = {}
+
+
+def reader_creator(filename, n):
+    global word_idx
+    if len(word_idx) == 0:
+        word_idx = build_dict('./simple-examples/data/ptb.train.txt',
+                              './simple-examples/data/ptb.valid.txt')
+
+    def reader():
+        with tarfile.open(
+                paddle.v2.dataset.common.download(
+                    paddle.v2.dataset.imikolov.URL, 'imikolov',
+                    paddle.v2.dataset.imikolov.MD5)) as tf:
+            f = tf.extractfile(filename)
+
+            ANY = word_idx['<any>']
+            for l in f:
+                l = ['<s>'] + l.strip().split() + ['<e>']
+                if len(l) >= n:
+                    l = [word_idx.get(w, ANY) for w in l]
+                    for i in range(n, len(l) + 1):
+                        yield l[i - n:i]
+
+    return reader
+
+
+def train(n):
+    return reader_creator('./simple-examples/data/ptb.train.txt', n)
+
+
+def test(n):
+    return reader_creator('./simple-examples/data/ptb.valid.txt', n)

python/paddle/v2/dataset/tests/imikolov_test.py

+import paddle.v2.dataset.imikolov
+import unittest
+
+
+class TestMikolov(unittest.TestCase):
+    def check_reader(self, reader, n):
+        for l in reader():
+            self.assertEqual(len(l), n)
+
+    def test_train(self):
+        n = 5
+        self.check_reader(paddle.v2.dataset.imikolov.train(n), n)
+
+    def test_test(self):
+        n = 5
+        self.check_reader(paddle.v2.dataset.imikolov.test(n), n)
+
+
+if __name__ == '__main__':
+    unittest.main()