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I have a couple different versions of Python installed on my Mac. The default version is 2.5, so when I install a module it gets installed to 2.5. I need to be able to install some modules to a different version of Python because I am working on projects that use different versions. Any one know how to accomplish this? Thanks for your help.

Sam
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  • For a similar question, on installing modules with `easy_install` when different versions of python, installed with macports ara available, see http://stackoverflow.com/questions/5792060/easy-install-with-various-versions-of-python-installed-mac-osx – juanchopanza Jun 03 '11 at 07:18

3 Answers3

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If you're installing using setup.py, just run it via the appropriate version of Python, e.g.:

python2.6 setup.py install

If you're using easy_install there should be a version for the corresponding Python version called easy_install-N.N, e.g.

easy_install-2.6 some_module

If you're working on different projects that require different versions of Python, consider using virtualenv (and virtualenvwrapper) - it allows you to fire up and use multiple environments each with its own version of Python and set of libraries. Example usage would be something like:

$ python -V
Python 2.5.4
$ mkvirtualenv --python=python2.6 foo
foo $ python -V
Python 2.6.1
foo $ pip install some_mod # installs module in foo's library, rather
                           # than site wide
foo $ deactivate # leave the virtual env
$ python -m some_mod
/path/to/python: No module named some_mod

To go back to the foo environment later, use workon:

$ workon foo
foo $ python -m some_mod # no error, apns available within the env
foo $

So you can use virtualenv to maintain separate environments for each version of Python you have installed. Within those environments, pip and easy_install just do the right thing.

Simon Whitaker
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  • How exactly do you get the version of easy_install that you need? None of the stuff I've ready is easy or points me to something that works. – Michael May 02 '14 at 22:28
  • Ok, apparently the package name is `setuptools` not `easy_install`. – Michael May 03 '14 at 15:24
3

If you're installing through setuptools (ie python setup.py), it will install to the lib directory for the python executable you use (unless it's a broken package).

Sean McSomething
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2

If you've installed them using then you run (as root):

port select --set python <python_version>

Hint: To list available versions run:

port select --list python

Otherwise you can set the $PYTHON_PATH environment variable and add your desired path to your $PATH environment variable as well.

You will also need to update the python.current (or something with similar name) symbolic link in /Library/Frameworks/Python.framework.

I strongly recommend to install all the versions using a package manager (, , , etc.) so they'll be easier to manage.

fardjad
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  • `port install python_select` seems to proceed okay, but there is no `python_select` binary afterwards... – Michael May 02 '14 at 22:32
  • `python_select` is deprecated. Do `sudo port select --set python (ex. python26)` instead. – fardjad May 03 '14 at 07:22