workflow.py 文件源码

def atomic_writer(file_path, mode):
    """Atomic file writer.

    :param file_path: path of file to write to.
    :type file_path: ``unicode``
    :param mode: sames as for `func:open`
    :type mode: string

    .. versionadded:: 1.12

    Context manager that ensures the file is only written if the write
    succeeds. The data is first written to a temporary file.

    """
    temp_suffix = '.aw.temp'
    temp_file_path = file_path + temp_suffix
    with open(temp_file_path, mode) as file_obj:
        try:
            yield file_obj
            os.rename(temp_file_path, file_path)
        finally:
            try:
                os.remove(temp_file_path)
            except (OSError, IOError):
                pass