def get_cipher(key=None, keyfile=None):
    des_func = import_attr(settings.SECRETKEY.CIPHER_CLS)
    kwargs = settings.SECRETKEY.CIPHER_ARGS
    
    if not key:
        key = functions.get_cipher_key(keyfile)
    cipher = des_func(key, **kwargs)
    return cipher
:param key: Either a serie name, or a tags_dict, or
dataset/ETHPy150Open limodou/uliweb/uliweb/contrib/secretkey/__init__.py/get_cipher--crossover with--dataset/ETHPy150Open influxdata/influxdb-python/influxdb/resultset.py/ResultSet.__getitem__