如何在Keras中添加变量到进度条？

from keras.callbacks import ProgbarLogger

# 创建一个自定义的回调函数，继承自ProgbarLogger
class CustomProgbarLogger(ProgbarLogger):
    def __init__(self, stateful_metrics=None):
        super(CustomProgbarLogger, self).__init__(stateful_metrics=stateful_metrics)

    def on_epoch_end(self, epoch, logs=None):
        # 在每个epoch结束时，将自定义变量添加到进度条中
        if self.stateful_metrics is not None:
            for metric in self.stateful_metrics:
                if metric in logs:
                    self.progbar.params[metric] = logs[metric]

        super(CustomProgbarLogger, self).on_epoch_end(epoch, logs)

# 创建模型并编译
model = ...
model.compile(...)

# 创建自定义的ProgbarLogger回调函数，并指定要添加的变量名称
custom_progbar = CustomProgbarLogger(stateful_metrics=['custom_variable'])

# 使用fit方法训练模型，并传入自定义的回调函数
model.fit(..., callbacks=[custom_progbar])