Issue #25523: Correct "a" article to "an" article
This changes the main documentation, doc strings, source code comments, and a
couple error messages in the test suite. In some cases the word was removed
or edited some other way to fix the grammar.
diff --git a/Modules/expat/pyexpatns.h b/Modules/expat/pyexpatns.h
index 2f2f4f9..999c5c7 100644
--- a/Modules/expat/pyexpatns.h
+++ b/Modules/expat/pyexpatns.h
@@ -21,7 +21,7 @@
*
*
* The Solution:
- * Prefix all a exported symbols with "PyExpat_". This is similar to
+ * Prefix all exported symbols with "PyExpat_". This is similar to
* what Mozilla does for some common libs:
* http://lxr.mozilla.org/seamonkey/source/modules/libimg/png/mozpngconf.h#115
*