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
to fix the grammar.
diff --git a/Lib/chunk.py b/Lib/chunk.py
index 3e3b5a4..2d15abe 100644
--- a/Lib/chunk.py
+++ b/Lib/chunk.py
@@ -21,7 +21,7 @@
usage of the Chunk class defined here is to instantiate an instance at
the start of each chunk and read from the instance until it reaches
the end, after which a new instance can be instantiated. At the end
-of the file, creating a new instance will fail with a EOFError
+of the file, creating a new instance will fail with an EOFError
exception.
Usage: