message: Update tensorflow/python/keras/callbacks.py
  Small bug in CSVLogger. Change the `open` function to `file_io.FileIO` to make it work with files stored on the cloud and not only locally.
diff: @@ -2745,14 +2745,13 @@ class CSVLogger(Callback):
  def on_train_begin(self, logs=None):
  if self.append:
  if file_io.file_exists_v2(self.filename):
  - with open(self.filename, 'r' + self.file_flags) as f:
  + with file_io.FileIO(self.filename, 'r' + self.file_flags) as f:
  self.append_header = not bool(len(f.readline()))
  mode = 'a'
  else:
  mode = 'w'
  - self.csv_file = io.open(self.filename,
  - mode + self.file_flags,
  - **self._open_args)
  + self.csv_file = file_io.FileIO(self.filename,
  + mode + self.file_flags)
  def on_epoch_end(self, epoch, logs=None):
  logs = logs or {}
  