2to3 will fail silently when building deap from sources using Python 3

[krypty]

When I try to build deap from sources using Python 3 inside a freshly created virtualenv, setuptools will simply ignore to run 2to3 if it is not installed in this virtualenv (proof: https://github.com/pypa/setuptools/blob/master/setuptools/command/build_py.py#L14). The result is that deap is built as a Python 2 package that is incompatible with Python 3.

Steps to reproduce

1. Create a new Python 3 virtualenv pyenv virtualenv 3.5.5 deap_creator
2. Activate it pyenv activate deap_creator
3. Run pip freeze and see that 2to3 is not installed
4. Install deap python setup.py install
5. Start a Python console and type from deap import creator
6. Then try to create a new class using creator : creator.create("Foo", list)
7. See the Python 2 error: AttributeError: 'dict' object has no attribute 'iteritems'

Proposed solution 1

Specify 2to3 as a requirement in setup.py. But I think this is not what deap is used to because otherwise other needed packages would be listed there too e.g. numpy.

Proposed solution 2

Add in the README if one wants to build deap from sources using Python 3 then one must install 2to3 package before and run the following commands:

pip install 2to3
2to3 -w .
python setup.py install