pth file overrides pythonpath

[Martin Pool]

python-lazr.restfulclient on natty installs /usr/share/pyshared/lazr.restfulclient-0.11.1-nspkg.pth with these contents:

import sys,types,os; p = os.path.join(sys._getframe(1).f_locals['sitedir'], *('lazr',)); ie = os.path.exists(os.path.join(p,'__init__.py')); m = not ie and sys.modules.setdefault('lazr',types.ModuleType('lazr')); mp = (m or []) and m.__dict__.setdefault('__path__',[]); (p not in mp) and mp.append(p)

This has at least three consequences:

1- if you have a different lazr.restfulclient module earlier on your PYTHONPATH, for instance if you're trying to fix a bug in it, you still get the installed version:

PYTHONPATH=~/src/lazr.restfulclient/src/ python -c 'import lazr.restfulclient;print lazr.restfulclient'
<module 'lazr.restfulclient' from '/usr/lib/python2.7/dist-packages/lazr/restfulclient/__init__.pyc'>

This is inconsistent with other Python modules.

2- Bizarrely, lazr looks like a built-in module:
% PYTHONPATH=~/src/lazr.restfulclient/src/ python -c 'import lazr;print lazr'
<module 'lazr' (built-in)>

3- The lazr module will be loaded every time Python is started, whether it is wanted or not, which is a (perhaps small) waste of time:

% python
Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.modules['lazr']
<module 'lazr' (built-in)>

Is this really necessary just to make a namespace package?

[Martin Pool (mbp)]

This also seems closely related to <http://comments.gmane.org/gmane.comp.version-control.bazaar-ng.general/72378>

   /usr/lib/python2.6/dist-packages/lazr/restfulclient/__init__.py:19: UserWarning: Module paste
was already imported from None, but /usr/lib/python2.6/dist-packages is being added to sys.path
          import pkg_resources

[Martin Pool (mbp)]

Jelmer suggests this might be different between python-central and python-support, and perhaps this is actually easier to fix on lucid (or not present on lucid) than on later series. Maybe we should migrate it to dh_python2.

[Launchpad Janitor (janitor)]

This bug was fixed in the package lazr.restfulclient - 0.13.1-1

---------------
lazr.restfulclient (0.13.1-1) experimental; urgency=low

  * New upstream release.
     - Now cache-safe for concurrent clients.
  * Upload to experimental, as we are in freeze.
  * Get rid of .pth files, dh_python2's namespace support is sufficient.
    (LP: #796992, #583426)
  * Depend on python-lazr.uri. (LP: #876445)
  * Update watch file to work with secure LP urls for the tarballs.
  * Bump Standards-Version to 3.9.4, no changes needed.
  * Bump machine readable copyright format to 1.0, no changes needed.
  * Updated copyright years.

 -- Stefano Rivera <email address hidden> Tue, 06 Nov 2012 11:53:59 +0200