From 9a80e00cac40dd64709919c29386d8ede39f91d6 Mon Sep 17 00:00:00 2001
From: "Andrew M. Kuchling" <amk@amk.ca>
Date: Fri, 21 Aug 1998 18:39:38 +0000
Subject: [PATCH] The .subn() method wasn't setting _num_regs, which is used by
 the .groups() 	method, so .groups() didn't work inside the replacement
 function 	called by re.sub.  One-line fix: set self._num_regs inside
 subn().

---
 Lib/re.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Lib/re.py b/Lib/re.py
index dce29ceac99..d190363df47 100644
--- a/Lib/re.py
+++ b/Lib/re.py
@@ -167,6 +167,7 @@ class RegexObject:
             regs = match(source, pos, end, 0)
             if not regs:
                 break
+            self._num_regs = len(regs)
             i, j = regs[0]
             if i == j == lastmatch:
                 # Empty match adjacent to previous match