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/Doc/c-api/buffer.rst b/Doc/c-api/buffer.rst
index d099ace..7361099 100644
--- a/Doc/c-api/buffer.rst
+++ b/Doc/c-api/buffer.rst
@@ -40,7 +40,7 @@
Simple objects such as :class:`bytes` and :class:`bytearray` expose their
underlying buffer in byte-oriented form. Other forms are possible; for example,
-the elements exposed by a :class:`array.array` can be multi-byte values.
+the elements exposed by an :class:`array.array` can be multi-byte values.
An example consumer of the buffer interface is the :meth:`~io.BufferedIOBase.write`
method of file objects: any object that can export a series of bytes through