Check a whitelist and/or blacklist to see if the value matches it.

def get_values_of_matching_keys(pattern_dict, user_name):
    '''
    Check a whitelist and/or blacklist to see if the value matches it.
    '''
    ret = []
    for expr in pattern_dict:
        if salt.utils.stringutils.expr_match(user_name, expr):
            ret.extend(pattern_dict[expr])
    return ret