Generator demonstrating countdown from a particular value.

.. literalinclude:: ../../languages/python/design_generator_countdown.py
   :language: python
   :tab-width: 4

.. runcode:: ../../languages/python/design_generator_countdown.py
   :language: python
   :codesite: ideone

.. seealso::

   * :python-suggest-improve:`design_generator_countdown.py`
   * :python-better-explain:`design_generator_countdown.rst`