def _existing_file_paths(self):
    data_paths = self._find_existing_data_paths()
    meta_paths = self._find_existing_meta_paths()
    assert (len(data_paths) == len(meta_paths))
    return zip(data_paths, meta_paths)
def _existing_file_paths(self):
    data_paths = self._find_existing_data_paths()
    meta_paths = self._find_existing_meta_paths()
    assert (len(data_paths) == len(meta_paths))
    return zip(data_paths, meta_paths)