【问题标题】:try to build functional api model in a class but raise NotImplementedError尝试在类中构建功能性 api 模型但引发 NotImplementedError
【发布时间】:2026-01-13 01:45:02
【问题描述】:
class MyModel(Model):

    def __init__(self,num_classes=1):
        super(MyModel, self).__init__()

        self.conv1=Convolution2D(filters=8,kernel_size=8,padding='same')
        self.batch_norm1=BatchNormalization()
        self.activation1=Activation('relu')
        self.conv2=Convolution2D(filters=16,kernel_size=8,activation='relu',padding='same')
        self.batch_norm2=BatchNormalization()
        self.activation2=Activation('relu')
        self.MaxPooling2D=MaxPooling2D(pool_size =(2, 2))
        self.Flatten=Flatten()
        self.dense1=Dense(16,activation='relu')
        self.dense2=Dense(num_classes,kernel_regularizer=regularizers.l2(0.4))

    def call(self,inputs):

        x=self.conv1(inputs)
        x=self.batch_norm1(x)
        x=self.activation1(x)
        x=self.conv2(x)
        x=self.batch_norm2(x)
        x=self.activation2(x)
        x=self.MaxPooling2D(x)
        x=self.Flatten(x)
        x=self.dense1(x)
        return self.dense2(x)

    def compute_output_shape(self, input_shape):

        shape = tf.TensorShape(input_shape).as_list()
        shape[-1] = self.num_classes
        return tf.TensorShape(shape)

model=MyModel()

adam=Adam(learning_rate=1e-4)

model.compile(optimizer=adam,loss="mse")

earlystopper = EarlyStopping(monitor='val_loss', patience=20, verbose=0) 

checkpoint =ModelCheckpoint("C:/Users/user/Desktop/research/pic_recognition/cnn2d-model.hdf5",save_best_only=True)

callback_list=[earlystopper,checkpoint]  

model.fit(x_train, y_train, epochs=50, batch_size=8,validation_split=0.1,callbacks=callback_list)

但我收到此错误:

文件“”,第 46 行,在 model.fit(x_train, y_train, epochs=50, batch_size=8,validation_split=0.1,callbacks=callback_list) 文件“D:\Anaconda3\lib\site-packages\keras\engine\training.py”,第 1239 行,适合 验证频率=验证频率) 文件“D:\Anaconda3\lib\site-packages\keras\engine\training_arrays.py”,第 216 行,在 fit_loop callbacks.on_epoch_end(epoch, epoch_logs) 文件“D:\Anaconda3\lib\site-packages\keras\callbacks\callbacks.py”,第 152 行,on_epoch_end callback.on_epoch_end(纪元,日志) 文件“D:\Anaconda3\lib\site-packages\keras\callbacks\callbacks.py”,第 719 行,on_epoch_end self.model.save(文件路径,覆盖=真) 文件“D:\Anaconda3\lib\site-packages\keras\engine\network.py”,第 1150 行,保存 引发 NotImplementedError 未实现错误

【问题讨论】:

    标签: python tensorflow keras


    【解决方案1】:

    对于自定义模型,您必须对 ModelCheckpoint() 使用“save_weights_only = True”或使用 model.save_weights()

    更多详情请参考以下链接:

    1. https://github.com/tensorflow/tensorflow/issues/22837

    2. https://github.com/keras-team/keras/issues/12922

    【讨论】: