Issue #26778: Fixed "a/an/and" typos in code comment and documentation.
diff --git a/Lib/test/test_extcall.py b/Lib/test/test_extcall.py
index babcce9..cb2c45e 100644
--- a/Lib/test/test_extcall.py
+++ b/Lib/test/test_extcall.py
@@ -282,7 +282,7 @@
     >>> f(**x)
     1 2
 
-A obscure message:
+An obscure message:
 
     >>> def f(a, b):
     ...    pass