parsers.py 文件源码

def parse_user_name(user_name: str) -> str:
    """Checks if ``user_name`` is valid.

    Parameters
    ----------
    user_name : str
        Possible user name.

    Returns
    -------
    user_name : str
        Valid user name.

    Raises
    ------
    click.BadParameter
        If user name is not valid.

    """
    if re.fullmatch(r'^[a-z][a-z0-9_]{5,}', user_name):
        return user_name
    else:
        raise click.BadParameter(
            'ERROR: Use at least six lower-case characters, '
            'digits and underscores.', param=user_name)