Hi, thanks for the comprehensive explanation! It clarifies things a lot.
Chris On Sun, Mar 22, 2009 at 8:23 PM, Ned Deily <n...@acm.org> wrote: > In article > <5465ee790903220622m7897dfcch7e8d838e6b429...@mail.gmail.com>, > Chris Van Bael <chris.van.b...@gmail.com> wrote: >> some simple questions: >> - if I installed another Python, how can I start it? Whenever I open >> a terminal and type "python", I get Python 2.5.1, which I assume is >> the Python from Apple. >> - On Windows there is the directory /Lib/site-packages, I can't find >> this one on my Mac. > > For python.org installers, each python major version lives in its own > framework sub-tree rooted at: > > /Library/Frameworks/Python.framework/Versions/m.n/ > > where m.n is 2.5, 2.6, 3.0, etc. > > At the top level of each version's subtree, there are bin, lib, include > and other directories. You'll find a pythonm.n executable and a python > symlink to it in the bin directory. > > Site packages for each version reside within its subtree lib directory > but normally you don't need to manipulate those directly. By default, > distutils (and its users, easy_install, pip, virtualenv et al) will > install extensions to the right site-library by running under the > setup.py script or easy_install or pip under the appropriate version of > the python executable. Extension scripts will also be installed in the > corresponding bin directory. > > So to select which python you want to start, you can invoke it directly > with: > > /Library/Frameworks/Python.framework/Versions/2.5/bin/python > > or modify your shell path to ensure that bin directory comes before > /usr/bin where the Apple-supplied python resides. Or create a shell > alias to it. Or use /usr/local/bin/pythonm.n because the python.org 2.x > installers create a link there by default - but beware because (1) that > doesn't help for installed scripts, (2) can be confusing with multiple > versions, and (3) by default the 3.x installers do not create that link. > > For development environments with multiple versions, a good solution > these days is to use virtualenv. Jesse Noller has a very good overview > of how to do that here: > > <http://jessenoller.com/2009/03/16/so-you-want-to-use-python-on-the-mac/> > > Again, all of the above applies to python.org installers. For the > record, the Apple-supplied python uses a more elaborate framework > scheme, split between /System/Library/Frameworks and /Library/Python, > with different defaults. macports uses a framework scheme rooted at > /opt/local/Library/Frameworks. And fink python installs are more > debian-y style non-framework layouts in /sw/{bin,lib,...}. > > -- > Ned Deily, > ...@acm.org > > _______________________________________________ > Pythonmac-SIG maillist - pythonmac-...@python.org > http://mail.python.org/mailman/listinfo/pythonmac-sig > _______________________________________________ Pythonmac-SIG maillist - Pythonmac-SIG@python.org http://mail.python.org/mailman/listinfo/pythonmac-sig
