def keyfmt(k, v=None):
    prefix = get_setting('CACHE_PREFIX')
    if v is None:
        key = prefix + k
    else:
        key = prefix + hashlib.md5((v % k).encode('utf-8')).hexdigest()
    return key.encode('utf-8')
dataset/ETHPy150Open jsocol/django-waffle/waffle/utils.py/keyfmt/swapped operands of `%`