Maintaining a backported module

[Christian Heimes]

Am 24.10.2013 06:54, schrieb Steven D'Aprano:
> As some of you are aware, I have a module accepted into the standard 
> library:
> 
> http://docs.python.org/3.4/library/statistics.html
> 
> I'm now at the point where I wish to backport this module to support 
> versions of Python back to 3.1 at least and possibly 2.7, and put it up 
> on PyPI.
> 
> I'm looking for advice on best practices for doing so. Any suggestions 
> for managing bug fixes and enhancements to two separate code-bases 
> without them diverging too much?

Hi Steven,

your module doesn't process text and doesn't use any fancy 3.x features
except raise from None. It should be just a matter of an hour or two to
port and package your code.

1) Add

    from __future__ import divisision

    import sys as _sys
    if _sys.version_info[0] == 2:
        range = xrange

to the top of your files to use 3.x integer division and generator range


2) Remove

  from None

in the exception handling code


3) Perhaps for 2.7 use iteritems in _sum()

  sorted(partials.items())


For testing under 2.6 you can use the unittest2 package. It offers all
the nice new features like assertIsInstance() and assertIn(). I highly
recommand tox + py.test for testing. You can test your package with all
versions of Python with just one command.

We already have a namespace for backports that you can use: backports.
:) Feel free to contact me via mail in #python-dev if you have any
questions.

Christian