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/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 9e62dfc..3f3b30f 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1418,7 +1418,7 @@
will not be usable in hashed collections. If a class defines mutable objects
and implements a :meth:`__cmp__` or :meth:`__eq__` method, it should not
implement :meth:`__hash__`, since hashable collection implementations require
- that a object's hash value is immutable (if the object's hash value changes,
+ that an object's hash value is immutable (if the object's hash value changes,
it will be in the wrong hash bucket).
User-defined classes have :meth:`__cmp__` and :meth:`__hash__` methods