Use raw-unicode-escape for the tests that require it.
diff --git a/Lib/test/test_format.py b/Lib/test/test_format.py
index a89ed52..127a407 100644
--- a/Lib/test/test_format.py
+++ b/Lib/test/test_format.py
@@ -214,5 +214,5 @@
test_exc('abc %a', 1, ValueError,
"unsupported format character 'a' (0x61) at index 5")
if have_unicode:
- test_exc(unicode('abc %\u3000'), 1, ValueError,
+ test_exc(unicode('abc %\u3000','raw-unicode-escape'), 1, ValueError,
"unsupported format character '?' (0x3000) at index 5")