Full_Name: Tim Peters Version: 1.5.2 OS: Win95 Submission from: 1cust154.tnt3.bos1.da.uu.net (153.34.162.154) >>> p = re.compile("(?P<a> a1) (?P<a> b2)") >>> p.groupindex {'a': 2} >>> re can't do anything sensible with a repeated group name, so it should complain about it instead of silently redefining it. Has come up a few times on c.l.py.