def _sudo_prefix(user, group=None):
    """
    Return ``env.sudo_prefix`` with ``user``/``group`` inserted if necessary.
    """
    # Insert env.sudo_prompt into env.sudo_prefix
    prefix = env % env.sudo_prefix
    if user is not None or group is not None:
        return "%s%s%s " % (prefix,
                            _sudo_prefix_argument('-u', user),
                            _sudo_prefix_argument('-g', group))
    return prefix
dataset/ETHPy150Open fabric/fabric/fabric/operations.py/_sudo_prefix/swapped operands of `%`