As mentioned in the last chapter, Python allows the writer of an
extension module to define new types that can be manipulated from
Python code, much like strings and lists in core Python.
This is not hard; the code for all extension types follows a pattern,
but there are some details that you need to understand before you can
The way new types are defined changed dramatically (and for the
better) in Python 2.2. This document documents how to define new
types for Python 2.2 and later. If you need to support older
versions of Python, you will need to refer to
older versions of this documentation.