In article <calzqqjbkh5cwrf6hpclc7nurkmbajutr3tyro_wqxjzl9vv...@mail.gmail.com>, Nat Echols <nathaniel.ech...@gmail.com> wrote: > I'm distributing a large cross-platform Python-based application, for which > we bundle Python 2.7 and a number of dependencies (wxPython, matplotlib, > etc.). We've tried to make it as self-contained as possible, to prevent > either a) polluting the user's environment and potentially breaking other > programs, or b) breaking our program because other software pollutes the > environment. This means wiping out PYTHONPATH at runtime, which has worked > quite well for us. > > What I've now discovered is that at least on OS 10.7.5, if a user installs > packages for the system python using easy_install (possibly other > mechanisms as well, but that's what "worked" for me), these will now end up > in the search path for our app's python interpreter, and override many of > the packages we distribute because they appear relatively early in > sys.path. The problem appears to be traceable to this file: > > /Library/Python/2.7/site-packages/easy-install.pth > > which modifies sys.path directly. Removing or renaming that file leaves > our custom distribution's path alone. So, two questions: > > 1) Why is this happening? It seems incredibly broken - but I have no idea > who's fault it is, for all I know we're doing something foolish when we > compile Python on our build system (10.6, if it matters). > > 2) Is there any way we can modify our distribution to avoid this?
The behavior is the result of a feature added in 2.7 for Issue4865 which appends the site-packages directory for the Apple-supplied system Python to sys.path of a Python framework build. With hindsight, I don't think this was a good idea and you are not the first to complain about it (see, for instance, Issue15048). OTOH, as Ronald pointed out in that issue, there isn't a complete separation between Python frameworks anyway: they all share the user site-packages directory (~/Library/Python for a framework build) and configuration files (like for Distutils and IDLE). It is late in the game to make a change like this in Python 2.7.x which is nearing the end of its supported life. It's not too late, IMO, to change current Python 3 before it becomes an issue; it's not an issue yet because Apple has not yet shipped anything newer than Python 2.7.x. Feel free to chime in on the bug tracker. The path appends occur in the standard library "site" module. You could patch it in your own interpreter to not include /Library/Python; you might be also be able to do it by supplying a "sitecustomize" module. See site.py for details. http://bugs.python.org/issue4865 http://bugs.python.org/issue15048 http://hg.python.org/cpython/file/2.7/Lib/site.py#l305 -- Ned Deily, n...@acm.org _______________________________________________ Pythonmac-SIG maillist - Pythonmac-SIG@python.org https://mail.python.org/mailman/listinfo/pythonmac-sig unsubscribe: https://mail.python.org/mailman/options/Pythonmac-SIG
