def iam_user_name(user_name):
    if (not user_name):
        raise ValueError("AWS::IAM::User property 'UserName' may not be empty")
    if (len(user_name) > 64):
        raise ValueError("AWS::IAM::User property 'UserName' may not exceed 64 characters")
    iam_user_name_re = compile('^[\\w+=,.@-]+$')
    if iam_user_name_re.match(user_name):
        return user_name
    else:
        raise ValueError("%s is not a valid value for AWS::IAM::User property 'UserName'", user_name)
def iam_user_name(user_name):
    if (not user_name):
        raise ValueError("AWS::IAM::User property 'UserName' may not be empty")
    if (len(user_name) > 64):
        raise ValueError("AWS::IAM::User property 'UserName' may not exceed 64 characters")
    iam_user_name_re = compile('^[\\w+=,.@-]+$')
    if iam_user_name_re.match(user_name):
        return user_name
    else:
        raise ValueError("%s is not a valid value for AWS::IAM::User property 'UserName'", user_name)