# File: grp-example-2.py

import grp
import os

# preload group dictionary
_grp = {}
for info in grp.getgrall():
    _grp[info[0]] = _grp[info[2]] = info

def groupinfo(gid):
    # name or gid integer
    return _grp[gid]

print groupinfo(os.getgid())
print groupinfo("wheel")