def reader(self):
    # If a multi-file pattern was specified as a source then make sure the
    # start/end offsets use the default values for reading the entire file.
    if re.search(r'[*?\[\]]', self.file_path) is not None:
      if self.start_offset is not None:
        raise ValueError(
            'start offset cannot be specified for a multi-file source: '
            '%s' % self.file_path)
      if self.end_offset is not None:
        raise ValueError(
            'End offset cannot be specified for a multi-file source: '
            '%s' % self.file_path)
      return TextMultiFileReader(self)
    else:
      return TextFileReader(self)
dataset/ETHPy150Open GoogleCloudPlatform/DataflowPythonSDK/google/cloud/dataflow/io/fileio.py/TextFileSource.reader/original