commit cd4dd9374d0fc65b070a61871801d306090f8375
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Mon Oct 01 22:12:02 2018 -0700
committer GitHub <noreply@github.com> Mon Oct 01 22:12:02 2018 -0700
tree 9034d7032562fa739ea857b15343758a730df793
parent 27d7f93f633f0163b96d0a95e312f0eb5615abfd

closes bpo-34868: Improve error message with '_' is combined with an invalid type specifier. (GH-9666)

(cherry picked from commit cbda8fc5d76b10bcbb92d927537576c229143836)

Co-authored-by: Benjamin Peterson <benjamin@python.org>

Lib/test/test_long.py

diff --git a/Lib/test/test_long.py b/Lib/test/test_long.py
index 8472889..b4a99e3 100644
--- a/Lib/test/test_long.py
+++ b/Lib/test/test_long.py
@@ -699,6 +699,9 @@
         self.assertRaisesRegex(ValueError, 'Cannot specify both', format, 3, '_,d')
         self.assertRaisesRegex(ValueError, 'Cannot specify both', format, 3, ',_d')
 
+        self.assertRaisesRegex(ValueError, "Cannot specify ',' with 's'", format, 3, ',s')
+        self.assertRaisesRegex(ValueError, "Cannot specify '_' with 's'", format, 3, '_s')
+
         # ensure that only int and float type specifiers work
         for format_spec in ([chr(x) for x in range(ord('a'), ord('z')+1)] +
                             [chr(x) for x in range(ord('A'), ord('Z')+1)]):