Python 2.7 module path problems on OS X
nad at acm.org
Sun Sep 5 11:20:24 CEST 2010
<AANLkTi=zZGOmi5NhYZCa7X9RBWu==oQzrZr4S876K2Eg at mail.gmail.com>,
Nicholas Cole <nicholas.cole at gmail.com> wrote:
> I have a horrible feeling that this is in some way related to the new
> user installation directory in 2.7,or some problem with the framework
> built, but I'm having great trouble with the module search path on
> I usually install modules to install_lib =
There are differences in defaults between different Python versions and
instances of the same version as built by different providers. The
pattern above is the default location for site-packages for
Apple-supplied Pythons in recent versions of OS X, in particular the
default /usr/bin/python2.6 in OS X 10.6 and /usr/bin/python2.5 in 10.5.
>> I assumed that this would continue to work on 2.7.
> Unfortunately, it seems not to. The installation is fine, but sys.path
> only includes
OTOH, the Python instances installed by the python.org OS X installers
(or ones built similarly) default to using the site-packages directory
in the framework directory as shown in that last path.
> Whereas on 2.6 on my system the default is the more extensive:
> I'm sorry to ask such a trivial question on the list, but I'm used to
> python installations "Just working"! Can anyone suggest a good fix?
I'm not sure why you think it is broken. The Apple 2.6 and the
python.org 2.7 have different site-package directories in different
locations. That is to be expected. The Apple-supplied Python comes
with some additional packages pre-installed, like setuptools, PyObjC,
and wx. But you would need to install new versions of these for 2.7
f you use "easy_install" (aka setuptools or Distribute), keep in mind
that every instance of Python needs to have its own version. So, for
2.7, you should follow the installation instructions for either
setuptools or Distribute and install a version for 2.7 using python2.7.
Its easy_install command will be in the framework bin directory,
/Library/Frameworks/Python.framework/Versions/2.7/bin, which is the
default location for scripts to be installed. You should ensure that
that directory appears on your shell PATH before /usr/bin (where the
Apple-supplied easy_install is); if you used the default settings for
the python.org installer, it will have attempted to modify your shell
startup files, like .bash_profile, to do that for you. Then you can use
that easy_install (also available as easy_install-2.7) to install
whatever packages you need for 2.7. Or you can use pip. Or just
manually installing using the package's setup.py script. All of them
use the Python instance's version of Distutils and it will do the right
thing for each instance as long as you don't try to influence things by
using non-default settings or setting Python-related environment
variables, like PYTHONPATH.
nad at acm.org
More information about the Python-list