commit da27d9b9dc44913ffee8f28d9638985eaaa03755
author Flavian Hautbois <flavianh@sicara.com> Sun Aug 25 21:06:45 2019 +0200
committer Berker Peksag <berker.peksag@gmail.com> Sun Aug 25 22:06:45 2019 +0300
tree 58520d3227798af6bdd60f90dae750c6ac58e933
parent 5dbe0f59b7a4f39c7c606b48056bc29e406ebf78

bpo-29553: Fix ArgumentParser.format_usage() for mutually exclusive groups (GH-14976)

Co-authored-by: Andrew Nester <andrew.nester.dev@gmail.com>

Lib/argparse.py

diff --git a/Lib/argparse.py b/Lib/argparse.py
index a300828..d29f161 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -404,13 +404,19 @@
                             inserts[start] += ' ['
                         else:
                             inserts[start] = '['
-                        inserts[end] = ']'
+                        if end in inserts:
+                            inserts[end] += ']'
+                        else:
+                            inserts[end] = ']'
                     else:
                         if start in inserts:
                             inserts[start] += ' ('
                         else:
                             inserts[start] = '('
-                        inserts[end] = ')'
+                        if end in inserts:
+                            inserts[end] += ')'
+                        else:
+                            inserts[end] = ')'
                     for i in range(start + 1, end):
                         inserts[i] = '|'