Re: [matplotlib-devel] namespace packages in toolkits?

On Thursday 13 December 2007 2:22:13 pm Robert Kern wrote:
> John Hunter wrote:
> > Do we need namespace packages in toolkits?  I recently added gtktools
> > and exceltools to toolkits, and got a very hard to debug error:
> >
> > In [1]: import matplotlib
> >
> > In [2]: matplotlib.__file__
> > Out[2]:
> > '/home/titan/johnh/dev/lib/python2.4/site-packages/matplotlib/__init__.py
> >c'
> >
> > In [3]: matplotlib.rcParams['axes.axisbelow']
> > Out[3]: False
> >
> > In [4]: import matplotlib.toolkits.gtktools
> >
> > In [5]: matplotlib.__file__
> > Out[5]:
> > '/opt/app/g++lib6/python-2.4/lib/python2.4/site-packages/matplotlib/__ini
> >t__.pyc'
> >
> > In [6]: matplotlib.rcParams['axes.axisbelow']
> > ------------------------------------------------------------
> > Traceback (most recent call last):
> >   File "<ipython console>", line 1, in ?
> > KeyError: 'axes.axisbelow'
> >
> > Notice that the matplotlib module which was previously imported got
> > changed by the import of the toolkit which declared itself a namespace
> > package.  Now this may be the result of mpl not using namespace
> > packages correctly (eg matplotlib/__init__.py should be empty save for
> > the namespace package or something like that)
>
> Probably. In setuptools 0.7, they can have stuff in them, but all of them
> must be identical.

How would one learn about this new feature? According to setuptools.txt from 
the 0.7 svn checkout, the namespace package's __init__.py must still be empty 
save the namespace declaration.

> If you are using an unmodified matplotlib/__init__.py in 
> the main matplotlib package, then the "if 0:" is preventing the declaration
> of the namespace package, and that may be contributing.
>
> Also, neither matplotlib nor matplotlib.toolkits is named as a
> namespace_package in matplotlib's setup.py, and both have to be. Similarly,
> basemap (for example) only lists matplotlib.toolkits but not matplotlib.

If I understand correctly, even after fixing these two problems, namespace 
packages would not work since matplotlib/__init__.py contains lots of 
meaningful code. Based on the remarks at 
http://mail.python.org/pipermail/distutils-sig/2007-October/008346.html and 
the setuptools svn commit log, it looks like development on version 0.7 is 
not a priority and a release in the next year is unlikely. So is it fair to 
say that for the foreseeable future, matplotlib is not compatible with 
namespace packages unless we cleaned out __init__.py? 

Darren