def chown(path, user=None, group=None):
    """Change owner user and group of the given path.
    user and group can be the uid/gid or the user/group names, and in that case,
    they are converted to their respective uid/gid.
    """
if user is None and group is None:
    raise ValueError('user and/or group must be set')
_user = user
_group = group
if user is None:
    _user = -1
elif isinstance(user, str):
    _user = _get_uid(user)
if _user is None:
    raise LookupError('no such user: {!r}'.format(user))
if group is None:
    _group = -1
elif not isinstance(group, int):
    _group = _get_gid(group)
if _group is None:
    raise LookupError('no such group: {!r}'.format(group))
os.chown(path, _user, _group)
How to change the user and group permissions for a directory, by name?