Keras自定义回调，保存历史字典和回调顺序

from keras.callbacks import Callback

class SaveHistory(Callback):
    def on_epoch_end(self, epoch, logs=None):
        if logs is None:
            logs = {}
        for k, v in logs.items():
            if k not in self.model.history:
                self.model.history[k] = []
            self.model.history[k].append(v)

from keras.callbacks import Callback

class CustomCallback(Callback):
    def on_train_begin(self, logs=None):
        # 在训练开始时执行的操作
        pass

    def on_epoch_begin(self, epoch, logs=None):
        # 在每个训练周期开始时执行的操作
        pass

    def on_epoch_end(self, epoch, logs=None):
        # 在每个训练周期结束时执行的操作
        pass

    def on_train_end(self, logs=None):
        # 在训练结束时执行的操作
        pass