What is the most compatible way to install python modules on a Mac?

Question

I'm starting to learn python and loving it. I work on a Mac mainly as well as Linux. I'm finding that on Linux (Ubuntu 9.04 mostly) when I install a python module using apt-get it works fine. I can import it with no trouble.

On the Mac, I'm used to using Macports to install all the Unixy stuff. However, I'm finding that most of the python modules I install with it are not being seen by python. I've spent some time playing around with PATH settings and using python_select . Nothing has really worked and at this point I'm not really understanding, instead I'm just poking around.

I get the impression that Macports isn't universally loved for managing python modules. I'd like to start fresh using a more "accepted" (if that's the right word) approach.

So, I was wondering, what is the method that Mac python developers use to manage their modules?

Bonus questions:

Do you use Apple's python, or some other version? Do you compile everything from source or is there a package manger that works well (Fink?).

Any tips or suggestions here are greatly appreciated. Thanks for your time. :)

Answer 1

Have you looked into easy_install at all? It won't synchronize your macports or anything like that, but it will automatically download the latest package and all necessary dependencies, i.e.

easy_install nose

for the nose unit testing package, or

easy_install trac

for the trac bug tracker.

There's a bit more information on their EasyInstall page too.

Answer 2

When you install modules with MacPorts, it does not go into Apple's version of Python. Instead those modules are installed onto the MacPorts version of Python selected.

You can change which version of Python is used by default using a mac port called python_select. instructions here.

Also, there's easy_install. Which will use python to install python modules.

Answer 3

The most popular way to manage python packages (if you're not using your system package manager) is to use setuptools and easy_install. It is probably already installed on your system. Use it like this:

easy_install django

easy_install uses the Python Package Index which is an amazing resource for python developers. Have a look around to see what packages are available.

A better option is pip, which is gaining traction, as it attempts to fix a lot of the problems associated with easy_install. Pip uses the same package repository as easy_install, it just works better. Really the only time use need to use easy_install is for this command:

easy_install pip

After that, use:

pip install django

At some point you will probably want to learn a bit about virtualenv. If you do a lot of python development on projects with conflicting package requirements, virtualenv is a godsend. It will allow you to have completely different versions of various packages, and switch between them easily depending your needs.

Regarding which python to use, sticking with Apple's python will give you the least headaches, but If you need a newer version (Leopard is 2.5.1 I believe), I would go with the macports python 2.6.

Answer 4

I use easy_install with Apple's Python, and it works like a charm.

Answer 5

Regarding which python version to use, Mac OS usually ships an old version of python. It's a good idea to upgrade to a newer version. You can download a .dmg from http://www.python.org/download/ . If you do that, remember to update the path. You can find the exact commands here http://farmdev.com/thoughts/66/python-3-0-on-mac-os-x-alongside-2-6-2-5-etc-/

Answer 6

Please see Python OS X development environment. The best way is to use MacPorts. Download and install MacPorts, then install Python via MacPorts by typing the following commands in the Terminal:

sudo port install python26 python_select
sudo python_select python26

OR

sudo port install python30 python_select
sudo python_select python30

Use the first set of commands to install Python 2.6 and the second set to install Python 3.0. Then use:

sudo port install py26-packagename

OR

sudo port install py30-packagename

In the above commands, replace packagename with the name of the package, for example:

sudo port install py26-setuptools

These commands will automatically install the package (and its dependencies) for the given Python version.

For a full list of available packages for Python, type:

port list | grep py26-

OR

port list | grep py30-

Which command you use depends on which version of Python you chose to install.

Answer 7

There's nothing wrong with using a MacPorts Python installation. If you are installing python modules from MacPorts but then not seeing them, that likely means you are not invoking the MacPorts python you installed to. In a terminal shell, you can use absolute paths to invoke the various Pythons that may be installed. For example:

$ /usr/bin/python2.5         # Apple-supplied 2.5 (Leopard)
$ /opt/local/bin/python2.5   # MacPorts 2.5
$ /opt/local/bin/python2.6   # MacPorts 2.6
$ /usr/local/bin/python2.6   # python.org (MacPython) 2.6
$ /usr/local/bin/python3.1   # python.org (MacPython) 3.1

To get the right python by default requires ensuring your shell $PATH is set properly to ensure that the right executable is found first. Another solution is to define shell aliases to the various pythons.

A python.org (MacPython) installation is fine, too, as others have suggested. easy_install can help but, again, because each Python instance may have its own easy_install command, make sure you are invoking the right easy_install.

Answer 8

I use MacPorts to install Python and any third-party modules tracked by MacPorts into /opt/local, and I install any manually installed modules (those not in the MacPorts repository) into /usr/local, and this has never caused any problems. I think you may be confused as to the use of certain MacPorts scripts and environment variables.

MacPorts python_select is used to select the "current" version of Python, but it has nothing to do with modules. This allows you to, e.g., install both Python 2.5 and Python 2.6 using MacPorts, and switch between installs.

The $PATH environment variables does not affect what Python modules are loaded. $PYTHONPATH is what you are looking for. $PYTHONPATH should point to directories containing Python modules you want to load. In my case, my $PYTHONPATH variable contains /usr/local/lib/python26/site-packages. If you use MacPorts' Python, it sets up the other proper directories for you, so you only need to add additional paths to $PYTHONPATH. But again, $PATH isn't used at all when Python searches for modules you have installed.

$PATH is used to find executables, so if you install MacPorts' Python, make sure /opt/local/bin is in your $PATH.

Answer 9

For MacPython installations, I found an effective solution to fixing the problem with setuptools (easy_install) in this blog post:

http://droidism.com/getting-running-with-django-and-macpython-26-on-leopard

One handy tip includes finding out which version of python is active in the terminal:

which python

Answer 10

If you use Python from MacPorts, it has it's own easy_install located at: /opt/local/bin/easy_install-2.6 (for py26, that is). It's not the same one as simply calling easy_install directly, even if you used python_select to change your default python command.