[Python-Dev] Why does Mac OS X python share site-packages with apple python?

[Barry Scott]

On 3 Mar 2012, at 21:57, Ned Deily wrote:

> In article <5A0E2490-A743-4729-A752-D94524EA9840 at barrys-emacs.org>,
> Barry Scott <barry at barrys-emacs.org> wrote:
>> On my Mac OS X 10.7.3 System I have lots of python kits installed for 
>> developing extensions.
>> 
>> I'll just noticed that Python.org 2.7.2 uses the sames site-packages folder 
>> with Apple's
>> 2.7.1.
>> 
>> Since extensions compiled against Apple's 2.7.1 segv when used by 
>> python.org's 2.7.2
>> this is at least unfortunate.
>> 
>> Here is the what is in sys.path for both versions. Notice 
>> /Library/Python/2.7/site-packages
>> is in both.
> 
> That directory is in the default sys.path for both the Apple-supplied 
> Python 2.7 in Lion and for the python.org Python 2.7's but that doesn't 
> mean both versions use the same site-packages directory:
> 
> $ /usr/bin/python2.7 -c "import distutils.sysconfig; \
>        print(distutils.sysconfig.get_python_lib())"
> /Library/Python/2.7/site-packages
> 
> $ /usr/local/bin/python2.7 -c "import distutils.sysconfig; \
>        print(distutils.sysconfig.get_python_lib())"
> /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-pack
> ages
> 
> That means that, by default, packages installed by Distutils-based 
> installs (setup.py, easy_install, pip, et al) will be installed to the 
> corresponding directory for each version.


> 
> The python.org OS X Pythons (and built-from-source framework builds) add 
> the Apple-specific directory to the search path in order to allow 
> sharing of installed third-party packages between the two.  The feature 
> was added in 2.7 and 3.1+ and tracked in Issue4865 
> (http://bugs.python.org/issue4865).  Please open a new issue on the 
> tracker if you have examples of how this is causing problems.  Thanks.
> 

Yes I have a example that SEGV, pysvn details of kit location in bug report.
I take it that any .so will crash as well. Only .py can be shared.

	http://bugs.python.org/issue14188

Look at the order of the sys.path the apple python site-packages
hides the python.org site-packages. If the shared folder was after
the python.org then imports could be made to work.

Barry