local.py 文件源码

def _key():
    global __key
    if __key:
        return __key

    data_dir = _key_dir()
    key_file = os.path.join(data_dir, 'key')

    if os.path.isfile(key_file):
        with open(key_file, 'rb') as f:
            __key = base64.b64decode(f.read())
            return __key

    __key = base64.b64encode(os.urandom(16))
    try:
        os.makedirs(data_dir)
    except OSError as e:
        # errno17 == dir exists
        if e.errno != 17:
            raise
    with open(key_file, 'wb') as f:
        f.write(__key)
    return __key