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.

1 files changed, 1 insertions, 1 deletions

diff --git a/Doc/library/chunk.rst b/Doc/library/chunk.rst
index 50b6979..a90e9f8 100644
--- a/Doc/library/chunk.rst
+++ b/Doc/library/chunk.rst
@@ -47,7 +47,7 @@ Usually an IFF-type file consists of one or more chunks.  The proposed usage of
 the :class:`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 :exc:`EOFError` exception.
+instance will fail with an :exc:`EOFError` exception.
 
 
 .. class:: Chunk(file, align=True, bigendian=True, inclheader=False)