Python keras.engine.training.Model() Examples

def test_trainable_argument():
    x = np.random.random((5, 3))
    y = np.random.random((5, 2))

    model = Sequential()
    model.add(Dense(2, input_dim=3, trainable=False))
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2)

    # test with nesting
    inputs = Input(shape=(3,))
    outputs = model(inputs)
    model = Model(inputs, outputs)
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2) 

def create_policy_value_net(self):
        """create the policy value network """   
        in_x = network = Input((4, self.board_width, self.board_height))

        # conv layers
        network = Conv2D(filters=32, kernel_size=(3, 3), padding="same", data_format="channels_first", activation="relu", kernel_regularizer=l2(self.l2_const))(network)
        network = Conv2D(filters=64, kernel_size=(3, 3), padding="same", data_format="channels_first", activation="relu", kernel_regularizer=l2(self.l2_const))(network)
        network = Conv2D(filters=128, kernel_size=(3, 3), padding="same", data_format="channels_first", activation="relu", kernel_regularizer=l2(self.l2_const))(network)
        # action policy layers
        policy_net = Conv2D(filters=4, kernel_size=(1, 1), data_format="channels_first", activation="relu", kernel_regularizer=l2(self.l2_const))(network)
        policy_net = Flatten()(policy_net)
        self.policy_net = Dense(self.board_width*self.board_height, activation="softmax", kernel_regularizer=l2(self.l2_const))(policy_net)
        # state value layers
        value_net = Conv2D(filters=2, kernel_size=(1, 1), data_format="channels_first", activation="relu", kernel_regularizer=l2(self.l2_const))(network)
        value_net = Flatten()(value_net)
        value_net = Dense(64, kernel_regularizer=l2(self.l2_const))(value_net)
        self.value_net = Dense(1, activation="tanh", kernel_regularizer=l2(self.l2_const))(value_net)

        self.model = Model(in_x, [self.policy_net, self.value_net])
        
        def policy_value(state_input):
            state_input_union = np.array(state_input)
            results = self.model.predict_on_batch(state_input_union)
            return results
        self.policy_value = policy_value 

def main_test():
    # loadFlickr8k() # load Flickr8k dataset for Image Description

    # loadMSVD() # load MSVD dataset for Video Description

    loadFood101()  # load Food101 dataset for Image Classification

    # Build basic model for image classification
    classifyFood101()


#################################
#
#    Model building functions
#
################################# 

def test_trainable_argument():
    x = np.random.random((5, 3))
    y = np.random.random((5, 2))

    model = Sequential()
    model.add(Dense(2, input_dim=3, trainable=False))
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2)

    # test with nesting
    inputs = Input(shape=(3,))
    outputs = model(inputs)
    model = Model(inputs, outputs)
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2) 

def test_trainable_argument():
    x = np.random.random((5, 3))
    y = np.random.random((5, 2))

    model = Sequential()
    model.add(Dense(2, input_dim=3, trainable=False))
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2)

    # test with nesting
    inputs = Input(shape=(3,))
    outputs = model(inputs)
    model = Model(inputs, outputs)
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2) 

def setOutputsMapping(self, outputsMapping, acc_output=None):
        """
            Sets the mapping of the outputs from the format given by the dataset to the format received by the model.

            :param outputsMapping: dictionary with the model outputs'
                                   identifiers as keys and the dataset outputs identifiers' position as values.
                                   If the current model is Sequential then keys must be ints with
                                   the desired output order (in this case only one value can be provided).
                                   If it is Model then keys must be str.
            :param acc_output: name of the model's output that will be used for calculating
                              the accuracy of the model (only needed for Graph models)
        """
        if isinstance(self.model, Sequential) and len(outputsMapping.keys()) > 1:
            raise Exception("When using Sequential models only one output can be provided in outputsMapping")
        self.outputsMapping = outputsMapping
        self.acc_output = acc_output 

def add_One_vs_One_Merge_Functional(self, inputs_list, nOutput, activation='softmax'):

        # join outputs from OneVsOne classifers
        ecoc_loss_name = 'ecoc_loss'
        final_loss_name = 'final_loss/out'
        ecoc_loss = merge(inputs_list, name=ecoc_loss_name, mode='concat', concat_axis=1)
        drop = Dropout(0.5, name='final_loss/drop')(ecoc_loss)
        # apply final joint prediction
        final_loss = Dense(nOutput, activation=activation, name=final_loss_name)(drop)

        in_node = self.model.layers[0].name
        in_node = self.model.get_layer(in_node).output
        self.model = Model(input=in_node, output=[ecoc_loss, final_loss])
        # self.model = Model(input=in_node, output=['ecoc_loss', 'final_loss'])

        return [ecoc_loss_name, final_loss_name] 

def VGG_19_ImageNet(self, nOutput, input):

        # Define inputs and outputs IDs
        self.ids_inputs = ['input_1']
        self.ids_outputs = ['predictions']

        # Load VGG19 model pre-trained on ImageNet
        self.model = VGG19(weights='imagenet', layers_lr=0.001)

        # Recover input layer
        image = self.model.get_layer(self.ids_inputs[0]).output

        # Recover last layer kept from original model
        out = self.model.get_layer('fc2').output
        out = Dense(nOutput, name=self.ids_outputs[0], activation='softmax')(out)

        self.model = Model(input=image, output=out)

    ########################################
    # GoogLeNet implementation from http://dandxy89.github.io/ImageModels/googlenet/
    ######################################## 

def test_trainable_argument():
    x = np.random.random((5, 3))
    y = np.random.random((5, 2))

    model = Sequential()
    model.add(Dense(2, input_dim=3, trainable=False))
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2)

    # test with nesting
    inputs = Input(shape=(3,))
    outputs = model(inputs)
    model = Model(inputs, outputs)
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2) 

def test_trainable_argument():
    x = np.random.random((5, 3))
    y = np.random.random((5, 2))

    model = Sequential()
    model.add(Dense(2, input_dim=3, trainable=False))
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2)

    # test with nesting
    inputs = Input(shape=(3,))
    outputs = model(inputs)
    model = Model(inputs, outputs)
    model.compile('rmsprop', 'mse')
    out = model.predict(x)
    model.train_on_batch(x, y)
    out_2 = model.predict(x)
    assert_allclose(out, out_2) 

def VGG_19(self, nOutput, input):

        # Define inputs and outputs IDs
        self.ids_inputs = ['input_1']
        self.ids_outputs = ['predictions']

        # Load VGG19 model pre-trained on ImageNet
        self.model = VGG19()

        # Recover input layer
        image = self.model.get_layer(self.ids_inputs[0]).output

        # Recover last layer kept from original model
        out = self.model.get_layer('fc2').output
        out = Dense(nOutput, name=self.ids_outputs[0], activation='softmax')(out)

        self.model = Model(input=image, output=out) 

def test_sparse_inputs_targets():
    test_inputs = [sparse.random(6, 3, density=0.25).tocsr() for _ in range(2)]
    test_outputs = [sparse.random(6, i, density=0.25).tocsr() for i in range(3, 5)]
    in1 = Input(shape=(3,))
    in2 = Input(shape=(3,))
    out1 = Dropout(0.5, name='dropout')(in1)
    out2 = Dense(4, name='dense_1')(in2)
    model = Model([in1, in2], [out1, out2])
    model.predict(test_inputs, batch_size=2)
    model.compile('rmsprop', 'mse')
    model.fit(test_inputs, test_outputs, epochs=1, batch_size=2, validation_split=0.5)
    model.evaluate(test_inputs, test_outputs, batch_size=2) 

def test_sparse_placeholder_fit():
    test_inputs = [sparse.random(6, 3, density=0.25).tocsr() for _ in range(2)]
    test_outputs = [sparse.random(6, i, density=0.25).tocsr() for i in range(3, 5)]
    in1 = Input(shape=(3,))
    in2 = Input(shape=(3,), sparse=True)
    out1 = Dropout(0.5, name='dropout')(in1)
    out2 = Dense(4, name='dense_1')(in2)
    model = Model([in1, in2], [out1, out2])
    model.predict(test_inputs, batch_size=2)
    model.compile('rmsprop', 'mse')
    model.fit(test_inputs, test_outputs, epochs=1, batch_size=2, validation_split=0.5)
    model.evaluate(test_inputs, test_outputs, batch_size=2) 

def test_warnings():
    a = Input(shape=(3,), name='input_a')
    b = Input(shape=(3,), name='input_b')

    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    b_2 = dp(b)

    model = Model([a, b], [a_2, b_2])

    optimizer = 'rmsprop'
    loss = 'mse'
    loss_weights = [1., 0.5]
    model.compile(optimizer, loss, metrics=[], loss_weights=loss_weights,
                  sample_weight_mode=None)

    def gen_data(batch_sz):
        while True:
            yield ([np.random.random((batch_sz, 3)), np.random.random((batch_sz, 3))],
                   [np.random.random((batch_sz, 4)), np.random.random((batch_sz, 3))])

    with pytest.warns(Warning) as w:
        out = model.fit_generator(gen_data(4), steps_per_epoch=10, use_multiprocessing=True, workers=2)
    warning_raised = any(['Sequence' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when using generator with processes.'

    with pytest.warns(None) as w:
        out = model.fit_generator(RandomSequence(3), steps_per_epoch=4, use_multiprocessing=True, workers=2)
    assert all(['Sequence' not in str(w_.message) for w_ in w]), 'A warning was raised for Sequence.' 

def test_trainable_weights_count_consistency():
    """Tests the trainable weights consistency check of Model.

    This verifies that a warning is shown if model.trainable is modified
    and the model is summarized/run without a new call to .compile()

    Reproduce issue #8121
    """
    a = Input(shape=(3,), name='input_a')
    model1 = Model(inputs=a, outputs=Dense(1)(a))

    model1.trainable = False
    b = Input(shape=(3,), name='input_b')
    y = model1(b)
    model2 = Model(inputs=b, outputs=Dense(1)(y))

    model2.compile(optimizer='adam', loss='mse')

    model1.trainable = True

    # Should warn on .summary()
    with pytest.warns(UserWarning) as w:
        model2.summary()
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And on .fit()
    with pytest.warns(UserWarning) as w:
        model2.fit(x=np.zeros((5, 3)), y=np.zeros((5, 1)))
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And shouldn't warn if we recompile
    model2.compile(optimizer='adam', loss='mse')
    with pytest.warns(None) as w:
        model2.summary()
    assert len(w) == 0, "Warning raised even when .compile() is called after modifying .trainable" 

def test_model_with_partial_loss():
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    a_3 = dp(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dropout': 'mse'}
    model.compile(optimizer, loss, metrics=['mae'])

    input_a_np = np.random.random((10, 3))
    output_a_np = np.random.random((10, 4))

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np])

    # Same without dropout.
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    a_3 = Dense(4, name='dense_2')(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dense_2': 'mse'}
    model.compile(optimizer, loss, metrics={'dense_1': 'mae'})

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np]) 

def test_warnings():
    a = Input(shape=(3,), name='input_a')
    b = Input(shape=(3,), name='input_b')

    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    b_2 = dp(b)

    model = Model([a, b], [a_2, b_2])

    optimizer = 'rmsprop'
    loss = 'mse'
    loss_weights = [1., 0.5]
    model.compile(optimizer, loss, metrics=[], loss_weights=loss_weights,
                  sample_weight_mode=None)

    def gen_data(batch_sz):
        while True:
            yield ([np.random.random((batch_sz, 3)), np.random.random((batch_sz, 3))],
                   [np.random.random((batch_sz, 4)), np.random.random((batch_sz, 3))])

    with pytest.warns(Warning) as w:
        out = model.fit_generator(gen_data(4), steps_per_epoch=10, use_multiprocessing=True, workers=2)
    warning_raised = any(['Sequence' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when using generator with processes.'

    with pytest.warns(None) as w:
        out = model.fit_generator(RandomSequence(3), steps_per_epoch=4, use_multiprocessing=True, workers=2)
    assert all(['Sequence' not in str(w_.message) for w_ in w]), 'A warning was raised for Sequence.' 

def test_sparse_placeholder_fit():
    test_inputs = [sparse.random(6, 3, density=0.25).tocsr() for _ in range(2)]
    test_outputs = [sparse.random(6, i, density=0.25).tocsr() for i in range(3, 5)]
    in1 = Input(shape=(3,))
    in2 = Input(shape=(3,), sparse=True)
    out1 = Dropout(0.5, name='dropout')(in1)
    out2 = Dense(4, name='dense_1')(in2)
    model = Model([in1, in2], [out1, out2])
    model.predict(test_inputs, batch_size=2)
    model.compile('rmsprop', 'mse')
    model.fit(test_inputs, test_outputs, epochs=1, batch_size=2, validation_split=0.5)
    model.evaluate(test_inputs, test_outputs, batch_size=2) 

def test_model_with_partial_loss():
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    a_3 = dp(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dropout': 'mse'}
    model.compile(optimizer, loss, metrics=['mae'])

    input_a_np = np.random.random((10, 3))
    output_a_np = np.random.random((10, 4))

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np])

    # Same without dropout.
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    a_3 = Dense(4, name='dense_2')(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dense_2': 'mse'}
    model.compile(optimizer, loss, metrics={'dense_1': 'mae'})

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np]) 

def test_warnings():
    a = Input(shape=(3,), name='input_a')
    b = Input(shape=(3,), name='input_b')

    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    b_2 = dp(b)

    model = Model([a, b], [a_2, b_2])

    optimizer = 'rmsprop'
    loss = 'mse'
    loss_weights = [1., 0.5]
    model.compile(optimizer, loss, metrics=[], loss_weights=loss_weights,
                  sample_weight_mode=None)

    def gen_data(batch_sz):
        while True:
            yield ([np.random.random((batch_sz, 3)), np.random.random((batch_sz, 3))],
                   [np.random.random((batch_sz, 4)), np.random.random((batch_sz, 3))])

    with pytest.warns(Warning) as w:
        out = model.fit_generator(gen_data(4), steps_per_epoch=10, use_multiprocessing=True, workers=2)
    warning_raised = any(['Sequence' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when using generator with processes.'

    with pytest.warns(None) as w:
        out = model.fit_generator(RandomSequence(3), steps_per_epoch=4, use_multiprocessing=True, workers=2)
    assert all(['Sequence' not in str(w_.message) for w_ in w]), 'A warning was raised for Sequence.' 

def load_model(model_path: Path) -> Model:
    return load_model_keras(str(model_path)) 

def test_trainable_weights_count_consistency():
    """Tests the trainable weights consistency check of Model.

    This verifies that a warning is shown if model.trainable is modified
    and the model is summarized/run without a new call to .compile()

    Reproduce issue #8121
    """
    a = Input(shape=(3,), name='input_a')
    model1 = Model(inputs=a, outputs=Dense(1)(a))

    model1.trainable = False
    b = Input(shape=(3,), name='input_b')
    y = model1(b)
    model2 = Model(inputs=b, outputs=Dense(1)(y))

    model2.compile(optimizer='adam', loss='mse')

    model1.trainable = True

    # Should warn on .summary()
    with pytest.warns(UserWarning) as w:
        model2.summary()
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And on .fit()
    with pytest.warns(UserWarning) as w:
        model2.fit(x=np.zeros((5, 3)), y=np.zeros((5, 1)))
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And shouldn't warn if we recompile
    model2.compile(optimizer='adam', loss='mse')
    with pytest.warns(None) as w:
        model2.summary()
    assert len(w) == 0, "Warning raised even when .compile() is called after modifying .trainable" 

def predictOnBatch(self, X, in_name=None, out_name=None, expand=False):
        """
            Applies a forward pass and returns the predicted values.
        """
        # Get desired input
        if in_name:
            X = copy.copy(X[in_name])

        # Expand input dimensions to 4
        if expand:
            while len(X.shape) < 4:
                X = np.expand_dims(X, axis=1)

        X = self.prepareData(X, None)[0]

        # Apply forward pass for prediction
        predictions = self.model.predict_on_batch(X)

        # Select output if indicated
        if isinstance(self.model, Model):  # Graph
            if out_name:
                predictions = predictions[out_name]
        elif isinstance(self.model, Sequential):  # Sequential
            predictions = predictions[0]

        return predictions

    # ------------------------------------------------------- #
    #       SCORING FUNCTIONS
    #           Functions for making scoring (x, y) samples
    # ------------------------------------------------------- # 

def test_model_with_partial_loss():
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    a_3 = dp(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dropout': 'mse'}
    model.compile(optimizer, loss, metrics=['mae'])

    input_a_np = np.random.random((10, 3))
    output_a_np = np.random.random((10, 4))

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np])

    # Same without dropout.
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    a_3 = Dense(4, name='dense_2')(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dense_2': 'mse'}
    model.compile(optimizer, loss, metrics={'dense_1': 'mae'})

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np]) 

def test_sparse_placeholder_fit():
    test_inputs = [sparse.random(6, 3, density=0.25).tocsr() for _ in range(2)]
    test_outputs = [sparse.random(6, i, density=0.25).tocsr() for i in range(3, 5)]
    in1 = Input(shape=(3,))
    in2 = Input(shape=(3,), sparse=True)
    out1 = Dropout(0.5, name='dropout')(in1)
    out2 = Dense(4, name='dense_1')(in2)
    model = Model([in1, in2], [out1, out2])
    model.predict(test_inputs, batch_size=2)
    model.compile('rmsprop', 'mse')
    model.fit(test_inputs, test_outputs, epochs=1, batch_size=2, validation_split=0.5)
    model.evaluate(test_inputs, test_outputs, batch_size=2) 

def test_sparse_inputs_targets():
    test_inputs = [sparse.random(6, 3, density=0.25).tocsr() for _ in range(2)]
    test_outputs = [sparse.random(6, i, density=0.25).tocsr() for i in range(3, 5)]
    in1 = Input(shape=(3,))
    in2 = Input(shape=(3,))
    out1 = Dropout(0.5, name='dropout')(in1)
    out2 = Dense(4, name='dense_1')(in2)
    model = Model([in1, in2], [out1, out2])
    model.predict(test_inputs, batch_size=2)
    model.compile('rmsprop', 'mse')
    model.fit(test_inputs, test_outputs, epochs=1, batch_size=2, validation_split=0.5)
    model.evaluate(test_inputs, test_outputs, batch_size=2) 

def test_model_with_partial_loss():
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    a_3 = dp(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dropout': 'mse'}
    model.compile(optimizer, loss, metrics=['mae'])

    input_a_np = np.random.random((10, 3))
    output_a_np = np.random.random((10, 4))

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np])

    # Same without dropout.
    a = Input(shape=(3,), name='input_a')
    a_2 = Dense(4, name='dense_1')(a)
    a_3 = Dense(4, name='dense_2')(a_2)
    model = Model(a, [a_2, a_3])

    optimizer = 'rmsprop'
    loss = {'dense_2': 'mse'}
    model.compile(optimizer, loss, metrics={'dense_1': 'mae'})

    # test train_on_batch
    out = model.train_on_batch(input_a_np, output_a_np)
    out = model.test_on_batch(input_a_np, output_a_np)
    # fit
    out = model.fit(input_a_np, [output_a_np])
    # evaluate
    out = model.evaluate(input_a_np, [output_a_np]) 

def test_warnings():
    a = Input(shape=(3,), name='input_a')
    b = Input(shape=(3,), name='input_b')

    a_2 = Dense(4, name='dense_1')(a)
    dp = Dropout(0.5, name='dropout')
    b_2 = dp(b)

    model = Model([a, b], [a_2, b_2])

    optimizer = 'rmsprop'
    loss = 'mse'
    loss_weights = [1., 0.5]
    model.compile(optimizer, loss, metrics=[], loss_weights=loss_weights,
                  sample_weight_mode=None)

    def gen_data(batch_sz):
        while True:
            yield ([np.random.random((batch_sz, 3)), np.random.random((batch_sz, 3))],
                   [np.random.random((batch_sz, 4)), np.random.random((batch_sz, 3))])

    with pytest.warns(Warning) as w:
        out = model.fit_generator(gen_data(4), steps_per_epoch=10, use_multiprocessing=True, workers=2)
    warning_raised = any(['Sequence' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when using generator with processes.'

    with pytest.warns(None) as w:
        out = model.fit_generator(RandomSequence(3), steps_per_epoch=4, use_multiprocessing=True, workers=2)
    assert all(['Sequence' not in str(w_.message) for w_ in w]), 'A warning was raised for Sequence.' 

def test_trainable_weights_count_consistency():
    """Tests the trainable weights consistency check of Model.

    This verifies that a warning is shown if model.trainable is modified
    and the model is summarized/run without a new call to .compile()

    Reproduce issue #8121
    """
    a = Input(shape=(3,), name='input_a')
    model1 = Model(inputs=a, outputs=Dense(1)(a))

    model1.trainable = False
    b = Input(shape=(3,), name='input_b')
    y = model1(b)
    model2 = Model(inputs=b, outputs=Dense(1)(y))

    model2.compile(optimizer='adam', loss='mse')

    model1.trainable = True

    # Should warn on .summary()
    with pytest.warns(UserWarning) as w:
        model2.summary()
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And on .fit()
    with pytest.warns(UserWarning) as w:
        model2.fit(x=np.zeros((5, 3)), y=np.zeros((5, 1)))
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And shouldn't warn if we recompile
    model2.compile(optimizer='adam', loss='mse')
    with pytest.warns(None) as w:
        model2.summary()
    assert len(w) == 0, "Warning raised even when .compile() is called after modifying .trainable" 

def test_trainable_weights_count_consistency():
    """Tests the trainable weights consistency check of Model.

    This verifies that a warning is shown if model.trainable is modified
    and the model is summarized/run without a new call to .compile()

    Reproduce issue #8121
    """
    a = Input(shape=(3,), name='input_a')
    model1 = Model(inputs=a, outputs=Dense(1)(a))

    model1.trainable = False
    b = Input(shape=(3,), name='input_b')
    y = model1(b)
    model2 = Model(inputs=b, outputs=Dense(1)(y))

    model2.compile(optimizer='adam', loss='mse')

    model1.trainable = True

    # Should warn on .summary()
    with pytest.warns(UserWarning) as w:
        model2.summary()
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And on .fit()
    with pytest.warns(UserWarning) as w:
        model2.fit(x=np.zeros((5, 3)), y=np.zeros((5, 1)))
    warning_raised = any(['Discrepancy' in str(w_.message) for w_ in w])
    assert warning_raised, 'No warning raised when trainable is modified without .compile.'

    # And shouldn't warn if we recompile
    model2.compile(optimizer='adam', loss='mse')
    with pytest.warns(None) as w:
        model2.summary()
    assert len(w) == 0, "Warning raised even when .compile() is called after modifying .trainable"