The short One Max genetic algorithm example is very similar to the full one :ref:`-ga-onemax`. The only difference is that it makes use of the :mod:`~deap.algorithms` module which implements some basic evolutionary algorithms. The initializations are almost the same. We only have to import some additional packages and modules.
.. literalinclude:: /../examples/ga/onemax_short.py :lines: 16,19-21
In order to use the evolution functions implemented in :mod:`~deap.algorithms`, we have to register some functions from the :mod:`~deap.tools` module: :func:`evaluate`, :func:`mate`, :func:`mutate`, and :func:`~deap.Toolbox.select`.
.. literalinclude:: /../examples/ga/onemax_short.py :lines: 41-44
The toolbox is then passed to the algorithm and via stats it uses the
registered functions.
.. literalinclude:: /../examples/ga/onemax_short.py :lines: 46, 49-58
The short GA One max example makes use of a :class:`~deap.tools.HallOfFame` in order to keep track of the best individual to appear in the evolution (it keeps it even in the case of extinction), and a :class:`~deap.tools.Statistics` object to compile the population statistics during the evolution.
Every algorithm in the :mod:`~deap.algorithms` module can handle these objects. Finally, the verbose keyword indicates whether we want the algorithm to output the results after each generation or not.
The complete source code: :example:`ga/onemax_short`.