test_initializer_nn.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 unittest

import paddle
import paddle.nn as nn
import paddle.fluid as fluid
import paddle.fluid.framework as framework
import paddle.nn.initializer as initializer
from paddle.fluid.core import VarDesc

DELTA = 0.00001


def get_uniform_min_and_max(weight):
    min_value = np.min(weight)
    max_value = np.max(weight)
    return min_value, max_value


def check_cast_op(op):
    return op.type == 'cast' and \
           op.attr('in_dtype') == VarDesc.VarType.FP32 and \
           op.attr('out_dtype') in [VarDesc.VarType.FP16, VarDesc.VarType.BF16]


class TestConstantInitializer(unittest.TestCase):

    def static_test_constant_initializer_common(self,
                                                init_inst,
                                                dtype="float32",
                                                value_target=0.0):
        paddle.enable_static()
        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype=dtype,
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=init_inst)
        num_ops = 1
        self.assertEqual(len(block.ops), num_ops)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'fill_constant')
        self.assertAlmostEqual(init_op.attr('value'), value_target, delta=DELTA)
        paddle.disable_static()
        return block

    def test_constant_initializer_default_value_static(self, dtype="float32"):
        """Test the constant initializer with default value in static graph
        """
        block = self.static_test_constant_initializer_common(
            init_inst=initializer.Constant(), dtype=dtype, value_target=0.0)
        return block

    def test_constant_initializer_default_value_dygraph(self, dtype="float32"):
        """Test constant initializer with supplied value in dygraph
        """
        with fluid.dygraph.guard():
            linear = nn.Linear(2, 4, weight_attr=nn.initializer.Constant())
            mat_target = np.ones((2, 4), dtype=dtype) * 0.0
            mat_linear = linear.weight.numpy()
            mismatch = np.sum(
                (mat_target - mat_linear) * (mat_target - mat_linear))
            self.assertAlmostEqual(mismatch, 0.0, delta=DELTA)

    def test_constant_initializer_static(self, dtype="float32"):
        """Test constant initializer with supplied value in static graph
        """
        block = self.static_test_constant_initializer_common(
            init_inst=initializer.Constant(2.3), dtype=dtype, value_target=2.3)
        return block

    def test_constant_initializer_dygraph(self, dtype="float32"):
        """Test constant initializer with supplied value in dygraph
        """
        with fluid.dygraph.guard():
            linear = nn.Linear(2,
                               4,
                               weight_attr=nn.initializer.Constant(value=2.0))
            mat_target = np.ones((2, 4), dtype=dtype) * 2.0
            mat_linear = linear.weight.numpy()
            mismatch = np.sum(
                (mat_target - mat_linear) * (mat_target - mat_linear))
            self.assertAlmostEqual(mismatch, 0.0, delta=DELTA)

    def test_constant_initializer_fp16(self):
        """Test constant initializer with float16
        """
        block = self.test_constant_initializer_default_value_static("float16")
        block = self.test_constant_initializer_static("float16")
        self.test_constant_initializer_default_value_dygraph("float16")
        self.test_constant_initializer_dygraph("float16")

    def test_constant_initializer_bf16(self):
        """Test constant initializer with bfloat16
            No cast operator has been added here
        """
        self.test_constant_initializer_default_value_static("uint16")  #bfloat16
        self.test_constant_initializer_static("uint16")  #bfloat16


class TestKaimingInitializer(unittest.TestCase):

    def static_test_kaiming_initializer_common(self,
                                               init_inst,
                                               dtype="float32",
                                               uniform=False,
                                               is_conv=False):
        paddle.enable_static()
        program = framework.Program()
        block = program.global_block()
        shape_mat = [5, 10, 15, 20] if is_conv else [5, 10]
        for _ in range(2):
            param = block.create_parameter(dtype="float32",
                                           shape=shape_mat,
                                           lod_level=0,
                                           name="param",
                                           initializer=init_inst)
        self.assertEqual(len(block.ops), 1)
        init_op = block.ops[0]
        if uniform:
            self.assertEqual(init_op.type, 'uniform_random')
            if is_conv:
                receptive_field_size = float(15 * 20)
                limit = np.sqrt(6.0 / (param.shape[1] * receptive_field_size))
            else:
                limit = np.sqrt(6.0 / param.shape[0])
            self.assertAlmostEqual(init_op.attr('min'), -limit, delta=DELTA)
            self.assertAlmostEqual(init_op.attr('max'), limit, delta=DELTA)
        else:
            self.assertEqual(init_op.type, 'gaussian_random')
            if is_conv:
                receptive_field_size = float(15 * 20)
                std = np.sqrt(2.0 / (param.shape[1] * receptive_field_size))
            else:
                std = np.sqrt(2.0 / param.shape[0])
            self.assertAlmostEqual(init_op.attr('mean'), 0.0, delta=DELTA)
            self.assertAlmostEqual(init_op.attr('std'), std, delta=DELTA)
        paddle.disable_static()

    def dygraph_test_kaiming_initializer_common(self,
                                                init_inst,
                                                dtype="float32",
                                                uniform=False):
        linear = nn.Linear(40, 20, weight_attr=init_inst)

    def test_kaiming_dygraph(self):
        self.dygraph_test_kaiming_initializer_common(
            init_inst=initializer.KaimingUniform(),
            dtype="float32",
            uniform=True)
        self.dygraph_test_kaiming_initializer_common(
            init_inst=initializer.KaimingNormal(),
            dtype="float32",
            uniform=False)

    def test_kaiming_uniform_initializer_static(self):
        """Test Kaiming unorm initializer for matrix multiply.
        """
        self.static_test_kaiming_initializer_common(
            init_inst=initializer.KaimingUniform(),
            dtype="float32",
            uniform=True,
            is_conv=False)

    def test_kaiming_uniform_initializer_conv_static(self):
        """Test Kaiming unorm initializer for convolutions.
        """
        self.static_test_kaiming_initializer_common(
            init_inst=initializer.KaimingUniform(),
            dtype="float32",
            uniform=True,
            is_conv=True)

    def test_kaiming_normal_initializer_static(self):
        """Test Kaiming normal initializer for matrix multiply.
        """
        self.static_test_kaiming_initializer_common(
            init_inst=initializer.KaimingNormal(),
            dtype="float32",
            uniform=False,
            is_conv=False)

    def test_kaiming_normal_initializer_conv_static(self):
        """Test Kaiming normal initializer for convolutions.
        """
        self.static_test_kaiming_initializer_common(
            init_inst=initializer.KaimingNormal(),
            dtype="float32",
            uniform=False,
            is_conv=True)


class TestUniform(unittest.TestCase):

    def test_uniform_common(self, dtype="float32", seed=0):
        """Test the uniform initializer with default value
        """
        paddle.enable_static()

        program = framework.Program()
        program.random_seed = seed
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype=dtype,
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.Uniform())
        num_ops = 2 if dtype == "float16" else 1
        self.assertEqual(len(block.ops), num_ops)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'uniform_random')
        self.assertAlmostEqual(init_op.attr('min'), -1.0, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('max'), 1.0, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), seed)

        paddle.disable_static()

        return block

    def test_uniform_initializer_default_value(self,
                                               dtype="float32",
                                               seed=0,
                                               min_value=-1.0,
                                               max_vlaue=1.0):
        """Test the uniform initializer with default value
        """
        paddle.enable_static()

        program = framework.Program()
        program.random_seed = seed
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype=dtype,
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.Uniform())
        num_ops = 2 if dtype == "float16" else 1
        self.assertEqual(len(block.ops), num_ops)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'uniform_random')
        self.assertAlmostEqual(init_op.attr('min'), min_value, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('max'), max_vlaue, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), seed)

        paddle.disable_static()

        return block

    def test_uniform_initializer(self,
                                 dtype="float32",
                                 seed=0,
                                 min_value=-4.2,
                                 max_vlaue=3.1):
        """Test uniform initializer with supplied attributes
        """
        paddle.enable_static()

        program = framework.Program()
        program.random_seed = seed
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype=dtype,
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.Uniform(
                                       min_value, max_vlaue))
        num_ops = 2 if dtype == "float16" else 1
        self.assertEqual(len(block.ops), num_ops)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'uniform_random')
        self.assertAlmostEqual(init_op.attr('min'), min_value, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('max'), max_vlaue, delta=DELTA)

        paddle.disable_static()

        return block

    def test_uniform_initializer_two_op(self,
                                        dtype="float32",
                                        seed=123,
                                        min_value=-4.2,
                                        max_vlaue=0.0):
        """Test uniform initializer with supplied attributes
        """
        paddle.enable_static()

        program = framework.Program()
        program.random_seed = seed
        block = program.global_block()
        for i in range(2):
            block.create_parameter(dtype=dtype,
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.Uniform(
                                       min_value, float(i)))
        num_ops = 2 if dtype == "float16" else 1
        self.assertEqual(len(block.ops), num_ops)
        init_op0 = block.ops[0]
        self.assertEqual(init_op0.type, 'uniform_random')
        self.assertAlmostEqual(init_op0.attr('min'), min_value, delta=DELTA)
        self.assertAlmostEqual(init_op0.attr('max'), 0.0, delta=DELTA)
        self.assertEqual(init_op0.attr("seed"), seed)

        paddle.disable_static()

        return block

    def test_uniform_initializer_fp16(self):
        """Test uniform initializer with float16
        """
        block = self.test_uniform_initializer_default_value("float16")
        self.assertTrue(check_cast_op(block.ops[1]))
        block = self.test_uniform_initializer(dtype="float16")
        self.assertTrue(check_cast_op(block.ops[1]))
        block = self.test_uniform_initializer_two_op("float16")
        self.assertTrue(check_cast_op(block.ops[1]))

    def test_uniform_initializer_bf16(self):
        """Test uniform initializer with bfloat16
        """
        block = self.test_uniform_initializer_default_value("uint16")  #bfloat16
        block = self.test_uniform_initializer(dtype="uint16")  #bfloat16
        block = self.test_uniform_initializer_two_op("uint16")  #bfloat16

    def test_uniform_initializer_dygraph(self):
        """Test uniform initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr = paddle.framework.ParamAttr(
            name="linear_weight",
            initializer=paddle.nn.initializer.Uniform(low=-0.5, high=0.5))
        linear = paddle.nn.Linear(2, 2, weight_attr=weight_attr)

        min_value, max_value = get_uniform_min_and_max(linear.weight.numpy())
        self.assertTrue(min_value >= -0.5,
                        'min value {} should >= -0.5'.format(min_value))
        self.assertTrue(max_value <= 0.5,
                        'max value {} should <= 0.5'.format(max_value))


class TestNormal(unittest.TestCase):

    def test_normal_initializer_default_value(self):
        """Test the normal initializer with default value
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype="float32",
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.Normal())
        self.assertEqual(len(block.ops), 1)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'gaussian_random')
        self.assertAlmostEqual(init_op.attr('mean'), 0.0, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('std'), 1.0, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), 0)

        paddle.disable_static()

    def test_normal_initializer(self, dtype="float32"):
        """Test normal initializer with supplied attributes
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype=dtype,
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.Normal(2.3, 1.9))
        num_ops = 1
        self.assertEqual(len(block.ops), num_ops)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'gaussian_random')
        self.assertAlmostEqual(init_op.attr('mean'), 2.3, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('std'), 1.9, delta=DELTA)

        paddle.disable_static()

        return block

    def test_normal_initializer_fp16(self):
        """Test normal initializer with float16
        """
        block = self.test_normal_initializer("float16")

    def test_normal_initializer_bf16(self):
        """Test normal initializer with bfloat16
        """
        block = self.test_normal_initializer("uint16")  #bfloat16

    def test_normal_initializer_dygraph(self):
        """Test normal initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr = paddle.framework.ParamAttr(
            name="linear_weight",
            initializer=paddle.nn.initializer.Normal(mean=0.0, std=2.0))
        linear = paddle.nn.Linear(2, 2, weight_attr=weight_attr)


class TestTruncatedNormal(unittest.TestCase):

    def test_truncated_normal_initializer_default_value(self):
        """Test the truncated normal initializer with default value
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype="float32",
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.TruncatedNormal())
        self.assertEqual(len(block.ops), 1)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'truncated_gaussian_random')
        self.assertAlmostEqual(init_op.attr('mean'), 0.0, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('std'), 1.0, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), 0)

        paddle.disable_static()

    def test_truncated_normal_initializer(self, dtype="float32"):
        """Test truncated normal initializer with supplied attributes
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            block.create_parameter(dtype=dtype,
                                   shape=[5, 10],
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.TruncatedNormal(
                                       2.3, 1.9))
        num_ops = 2 if dtype in ["float16", "uint16"] else 1
        self.assertEqual(len(block.ops), num_ops)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'truncated_gaussian_random')
        self.assertAlmostEqual(init_op.attr('mean'), 2.3, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('std'), 1.9, delta=DELTA)

        paddle.disable_static()

        return block

    def test_truncated_normal_initializer_fp16(self):
        """Test truncated normal initializer with float16
        """
        paddle.enable_static()

        block = self.test_truncated_normal_initializer("float16")
        self.assertTrue(check_cast_op(block.ops[1]))

    def test_truncated_normal_initializer_bf16(self):
        """Test truncated normal initializer with bfloat16
        """
        paddle.enable_static()

        block = self.test_truncated_normal_initializer("uint16")  #bfloat16
        self.assertTrue(check_cast_op(block.ops[1]))

    def test_truncated_normal_initializer_dygraph(self):
        """Test truncated normal initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr = paddle.framework.ParamAttr(
            name="linear_weight",
            initializer=paddle.nn.initializer.TruncatedNormal(mean=0.0,
                                                              std=2.0))
        linear = paddle.nn.Linear(2, 2, weight_attr=weight_attr)


class TestXavierUniform(unittest.TestCase):

    def test_xavier_uniform_initializer(self):
        """Test Xavier initializer with uniform distribution on
           for matrix multiply.
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            param = block.create_parameter(
                dtype="float32",
                shape=[5, 10],
                lod_level=0,
                name="param",
                initializer=initializer.XavierUniform())
        self.assertEqual(len(block.ops), 1)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'uniform_random')
        limit = np.sqrt(6.0 / (param.shape[0] + param.shape[1]))
        self.assertAlmostEqual(init_op.attr('min'), -limit, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('max'), limit, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), 0)

        paddle.disable_static()

    def test_xavier_uniform_initializer_conv(self):
        """Test Xavier initializer with uniform distribution on
           for convolutions.
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            param = block.create_parameter(
                dtype="float32",
                shape=[5, 10, 15, 20],
                lod_level=0,
                name="param",
                initializer=initializer.XavierUniform())
        self.assertEqual(len(block.ops), 1)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'uniform_random')
        receptive_field_size = float(15 * 20)
        limit = np.sqrt(
            6.0 / ((param.shape[0] + param.shape[1]) * receptive_field_size))
        self.assertAlmostEqual(init_op.attr('min'), -limit, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('max'), limit, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), 0)

    def test_xavier_uniform_initializer_dygraph(self):
        """Test xavier uniform initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr = paddle.framework.ParamAttr(
            name="linear_weight",
            initializer=paddle.nn.initializer.XavierUniform())
        linear = paddle.nn.Linear(2, 2, weight_attr=weight_attr)


class TestXavierNormal(unittest.TestCase):

    def test_xavier_normal_initializer(self):
        """Test Xavier initializer with normal distribution on
           for matrix multiply.
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            param = block.create_parameter(
                dtype="float32",
                shape=[5, 10],
                lod_level=0,
                name="param",
                initializer=initializer.XavierNormal())
        self.assertEqual(len(block.ops), 1)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'gaussian_random')
        std = np.sqrt(2.0 / (param.shape[0] + param.shape[1]))
        self.assertAlmostEqual(init_op.attr('mean'), 0.0, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('std'), std, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), 0)

        paddle.disable_static()

    def test_xavier_normal_initializer_conv(self):
        """Test Xavier initializer with normal distribution on
           for convolutions.
        """
        paddle.enable_static()

        program = framework.Program()
        block = program.global_block()
        for _ in range(2):
            param = block.create_parameter(
                dtype="float32",
                shape=[5, 10, 15, 20],
                lod_level=0,
                name="param",
                initializer=initializer.XavierNormal())
        self.assertEqual(len(block.ops), 1)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'gaussian_random')
        receptive_field_size = float(15 * 20)
        std = np.sqrt(
            2.0 / ((param.shape[0] + param.shape[1]) * receptive_field_size))
        self.assertAlmostEqual(init_op.attr('mean'), 0.0, delta=DELTA)
        self.assertAlmostEqual(init_op.attr('std'), std, delta=DELTA)
        self.assertEqual(init_op.attr('seed'), 0)

        paddle.disable_static()

    def test_xavier_normal_initializer_dygraph(self):
        """Test xavier normal initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr = paddle.framework.ParamAttr(
            name="linear_weight",
            initializer=paddle.nn.initializer.XavierNormal())
        linear = paddle.nn.Linear(2, 2, weight_attr=weight_attr)


class TestAssign(unittest.TestCase):

    def test_assign_initializer(self, dtype="float32"):
        """Test the numpy array initializer with supplied arguments
        """
        paddle.enable_static()

        import numpy
        program = framework.Program()
        block = program.global_block()
        np_array = numpy.random.random((10000)).astype(dtype)
        for _ in range(2):
            block.create_parameter(dtype=np_array.dtype,
                                   shape=np_array.shape,
                                   lod_level=0,
                                   name="param",
                                   initializer=initializer.Assign(np_array))
        num_ops = 2 if dtype in ["float16", "uint16"] else 1
        self.assertEqual(len(block.ops), num_ops)
        init_op = block.ops[0]
        self.assertEqual(init_op.type, 'assign_value')
        assert (init_op.attr('fp32_values') == np_array).all()

        paddle.disable_static()

        return block

    def test_assign_initializer_fp16(self):
        """Test the numpy array initializer with float16
        """
        block = self.test_assign_initializer("float16")
        self.assertTrue(block.ops[1])

    def test_assign_initializer_bf16(self):
        """Test the numpy array initializer with bfloat16
        """
        block = self.test_assign_initializer("uint16")  #bfloat16
        self.assertTrue(block.ops[1])

    def test_assign_initializer_dygraph_1(self):
        """Test assign initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr_1 = paddle.framework.ParamAttr(
            name="linear_weight_1",
            initializer=paddle.nn.initializer.Assign(np.array([2, 2])))
        linear_1 = paddle.nn.Linear(2, 2, weight_attr=weight_attr_1)

        self.assertTrue((linear_1.weight.numpy() == [2.0, 2.0]).all(), '')

    def test_assign_initializer_dygraph_2(self):
        """Test assign initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr_2 = paddle.framework.ParamAttr(
            name="linear_weight_2",
            initializer=paddle.nn.initializer.Assign([2, 2]))
        linear_2 = paddle.nn.Linear(2, 2, weight_attr=weight_attr_2)

        self.assertTrue((linear_2.weight.numpy() == [2.0, 2.0]).all(), '')

    def test_assign_initializer_dygraph_3(self):
        """Test assign initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr_3 = paddle.framework.ParamAttr(
            name="linear_weight_3",
            initializer=paddle.nn.initializer.Assign(paddle.full([2], 2)))
        linear_3 = paddle.nn.Linear(2, 2, weight_attr=weight_attr_3)

        self.assertTrue((linear_3.weight.numpy() == [2.0, 2.0]).all(), '')

    def test_assign_initializer_dygraph_4(self):
        """Test assign initializer in dygraph model.
        """
        paddle.disable_static()

        weight_attr_4 = paddle.framework.ParamAttr(
            name="linear_weight_4",
            initializer=paddle.nn.initializer.Assign((2, 2)))
        linear_4 = paddle.nn.Linear(2, 2, weight_attr=weight_attr_4)

        self.assertTrue((linear_4.weight.numpy() == [2.0, 2.0]).all(), '')


if __name__ == '__main__':
    unittest.main()