def prefix_dict_keys(dictionary, prefix='_'):
    """
    Prefix dictionary keys with a provided prefix.

    :param dictionary: Dictionary whose keys to prefix.
    :type dictionary: ``dict``

    :param prefix: Key prefix.
    :type prefix: ``str``

    :rtype: ``dict``:
    """
    result = {}

    for key, value in six.iteritems(dictionary):
        result[(prefix, key) % '%s%s'] = value

    return result
dataset/ETHPy150Open StackStorm/st2/st2common/st2common/util/misc.py/prefix_dict_keys/swapped operands of `%`