Python 3.7.3 : The sip python module.

The official webpage pypi.org comes with this intro:
One of the features of Python that makes it so powerful is the ability to take existing libraries, written in C or C++, and make them available as Python extension modules. Such extension modules are often called bindings for the library.

SIP is a tool that makes it very easy to create Python bindings for C and C++ libraries. It was originally developed to create PyQt, the Python bindings for the Qt toolkit, but can be used to create bindings for any C or C++ library.

SIP comprises a code generator and a Python module. The code generator processes a set of specification files and generates C or C++ code which is then compiled to create the bindings extension module. The sip Python module provides support functions to the automatically generated code.
The SIP is copyright (c) Riverbank Computing Limited and its homepage is this webpage.
Support may be obtained from the PyQt mailing list at here.
The SIP is a tool for quickly writing Python modules that interface with C++ and C libraries.
The SIP comprises a code generator and a Python module.
About the code generator:
First, the install:

C:\Python373\Scripts>pip3 install sip
Collecting sip
...
Installing collected packages: sip
Successfully installed sip-4.19.8

If you using the PyQt5 then this version includes a private copy of the module.

C:\Python373>python.exe
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 21:26:53) [MSC v.1916 32 bit (Inte
l)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from PyQt5 import sip

If you want to see backward compatibility the module then needs to imported and will only work if another PyQt5 module is imported first.

C:\Python373>python.exe
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 21:26:53) [MSC v.1916 32 bit (Inte
l)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> from PyQt5 import QtCore
>>> import sip

A good example of how can you build with SIP can be seen here.
About the SIP Python module:
This provides support functions to the automatically generated code.
The import python module sip let you use all functions build by the code generator:

>>> dir(sip)
['SIP_VERSION', 'SIP_VERSION_STR', '_C_API', '__doc__', '__file__', '__loader__'
, '__name__', '__package__', '__spec__', '_unpickle_enum', '_unpickle_type', 'as
sign', 'cast', 'delete', 'dump', 'enableautoconversion', 'enableoverflowchecking
', 'getapi', 'isdeleted', 'ispycreated', 'ispyowned', 'setapi', 'setdeleted', 's
etdestroyonexit', 'settracemask', 'simplewrapper', 'transferback', 'transferto',
 'unwrapinstance', 'voidptr', 'wrapinstance', 'wrapper', 'wrappertype']

If you want to improve or create python modules with C or C ++, then this tool can help.