import sys
import string

_maketrans = str.maketrans if sys.version_info[0] == 3 else string.maketrans
_ircstring_translation = _maketrans(
    string.ascii_lowercase.upper() + "[]\\^",
    string.ascii_lowercase + "{}|~")

def irc_lower(s):
    return string.translate(s, _ircstring_translation)