The modules described in this chapter help you write software. For example, the :mod:`pydoc` module takes a module and generates documentation based on the module's contents. The :mod:`doctest` and :mod:`unittest` modules contains frameworks for writing unit tests that automatically exercise code and verify that the expected output is produced. :program:`2to3` can translate Python 2.x source code into valid Python 3.x code.

The list of modules described in this chapter is:

.. toctree::

   typing.rst
   pydoc.rst
   doctest.rst
   unittest.rst
   unittest.mock.rst
   unittest.mock-examples.rst
   2to3.rst
   test.rst