Develop Reference

Python on Yosemite

Just got a new Mac with Yosemite. Ran the Migration Assistant to move files over from older machine. Now I find myself with an "old" (2.7.2) version of Python that doesn't work on Yosemite (crash at second line of interactive command line).
Either Apple ships Yosemite with a really old version of Python, or MA decided to overwrite the one that was there with an older one from my old machine?
Hoping that there is a way to solve this that doesn't involve multiple manual steps... but I haven't found an obvious way. Any Pythonistas out there that have a magic bullet for me?
Also - is this the right forum for this question or should I move it to Ask Different (apple.stackexchange.com)?

You undoubtedly had another version of Python installed, independent of the Apple-supplied system Pythons, which was migrated. If you used python.org installers, that Python would be in /Library/Frameworks. If you use a third-party package manager, like MacPorts or Homebrew, it is likely somewhere else. You can use type python to find out where you are picking up Python from and then either upgrade it or remove it. Do not try to remove the Apple Pythons in /System/Library/Frameworks. With Yosemite, Apple ships 2.7.6. You can either upgrade the additional Python, for example, by downloading and installing the latest Python 2 from python.org (currently 2.7.9), or follow the instructions here to remove it.

pyHook for Python 3.3

I am coding a simple keylogger using Python. I hope to use pyHook to capture keyboard events.I couldn't find any packages of pyHook for python 3.3 which I have installed. Is there any other module for python 3.3 which provides similar functionalities?

A quick google turned up this site, which has unofficial installers for pyHook 1.5.1 (and a whole lot of other packages) for Python 3.3. I haven't tested it, but it seems worth trying. And there are a couple of other similar repositories on the first page of Google results if this one doesn't work.
I also found a few forks on github, like this one, which have fixes for Unicode bugs in 3.x. I have no idea if those bugs have been fixed in the main pyHook project (or made it into the 1.5.1 release), but if you run into problems, you may want to take a look.
You'd have a lot more options if you installed a compiler (MinGW and/or Visual Studio Express) and used easy_install or pip to install packages automatically, building them from source if necessary. Then you wouldn't need to search for binary installers for everything.

The inofficial installers mentioned by abarnert seem to work fine. They provide installers for almost every version of Python - except for 3.5, which is currently considered unstable anyway (07/10/14), so that's not a big issue.

Questions about Django development on Mac OS X

I'm new to Mac (as of yesterday), and I have Snow Leopard. I've just easy_install virtualenv, and it doesn't work. I read a couple other SO questions about the same exception I had, and it seems that I need XCode installed. Before I go down a rabbit hole, installing a 3.5Gb Apple-specific code library for something Python related, and who knows what else at this point, I figured I'd stop by here and find out what's typical for Django developers with Macs.
What tools / libraries that are Python/Django specific, but non-project specific do you commonly use?
Is XCode really necessary to use virtualenv (and potentially other things, or is this just one way to solve my issue?
Are there other Mac issues that you've run into with basic Django development?
Do you have any other tips for a veteran Django dev who is an absolute Mac noob?

You will need XCode, yes. You'll need it for any libraries that need compiling, apart from anything else.
Please don't install MacPorts, though, as recommended by titaniumdecoy. It tries to install its own versions of everything, which is unnecessarily confusing, and takes you out of the usual Mac development stack. A much better package installation tool is homebrew, which uses the built-in tools to install software via a series of recipes. It's excellent.

I started use Mac a couple days ago and I have same problem. You need XCode, yes!
Packgers manager, like apt-get, you can try HomeBrew.
To develop in django, I use TextMate, with some bundles to django.
To develop in python I use pip, virtualenv and virtualenvwrapper, this is awesome.

As an iOS developer I can't comment on the specifics of Django development, but the following should help get you started.
Install macports immediately. You can install virtually any unix tool you can think of with a single command, including virtualenv. (Update: Use HomeBrew instead as suggested in other answers: see comments for why.)
You need to install Xcode to get the Mac OS X developer toolchain (gcc, etc.) unless you prefer to install everything yourself.
If you use Eclipse, the Pydev plug-in is one way to go. TextMate is probably the most popular text editor on the mac. The Python Wiki has a comprehensive rundown of your options.

Recommendations for Python development on a Mac?

I bought a low-end MacBook about a month ago and am finally getting around to configuring it for Python. I've done most of my Python work in Windows up until now, and am finding the choices for OS X a little daunting. It looks like there are at least five options to use for Python development:
"Stock" Apple Python
MacPython
Fink
MacPorts
roll-your-own-from-source
I'm still primarily developing for 2.5, so the stock Python is fine from a functionality standpoint. What I want to know is: why should I choose one over the other?
Update:
To clarify, I am looking for a discussion of the various options, not links to the documentation. I've marked this as a Community Wiki question, as I don't feel there is a "correct" answer. Thanks to everyone who has already commented for their insight.

One advantage I see in using the "stock" Python that's included with Mac OS X is that it makes deployment to other Macs a piece of cake. I don't know what your deployment scenario is, but for me this is important. My code has to run on any number of Macs at work, and I try to minimize the amount of work it takes to run my code on all of those systems.

I would highly recommend using MacPorts with Porticus for managing your Python installation. It takes a while to build everything, but the advantage is that whatever you build yourself will be built against the same libraries, so you won't have to futz around with statically linked shared objects, etc. if you want your Python stuff to work with Apache, PostgreSQL, etc.
If you choose to go this way, remember to install the python_select port and use it to make your system use the Python installed from MacPorts.
As an added bonus, MacPorts has packages for most main-stream Python eggs, so if you should be able to have MacPorts keep you up-to-date with the latest versions of all that stuff :)

Here's some helpful info to get you started. http://www.python.org/download/mac/

Depends what you are using python for. If you are using MacOS funitionality and things like PyObjC you are probably best of with MacPython or the python provided by Apple.
I use Python on my Mac mostly for development of server side applications which later will run on FreeBSD & Linux boxes. For that I have used fink python for a few years and ever since MacPorts python. With mac ports it is simple to add required c modules (like database driver etc). It's also easy to keep two python Versions (2.5 & 2.6 in my case) around.
I used "compile your own" python to test pre-3.0 python but generally I find managing dependencies to c modules painfull if done by hand.
Thanks to easy_install installing pure python modules is fast and easy for all the options mentioned above.
I was never very much an IDE person. For development I use command line subversion installed by MacPorts, Textmate and occasionaly Expandrive do directly access files on servers. I personally are very dependent on Bicyclerepairman for Textmade to handle my refactoring needs.
Others seem to be very happy with Eclipse & Pydev.

How about EPD from Enthought? Yes, it's large but it is a framework build and includes things like wxPython, vtk, numpy, scipy, and ipython built-in.

I recommend using Python Virtual environments, especially if you use a Timecapsule because Timecapsule will back everything up, except modules you added to Python!

Based on the number of bugs and omissions people have been encountering in Leopard python (just here on SO!), I couldn't recommend that version. e.g., see:
Why do I get wrong results for hmac in Python but not Perl?
Problems on select module on Python 2.5
I would choose MacPorts.
It does not eliminate your existing python supplied by Apple since it installs by default in /opt/local/bin (plays nice with it) and plus it is easy to download and install additional python modules (even binary modules that you need to compile!). I use Porticus GUI to maintain my MacPorts installed list of packages, including python.

In my windows environment I use Eclipse and PyDev, which works quite well together, even if it's a bit sparse. Apparently the exact same environment is available for the Mac as well, so I suggest downloading Eclipse and using the internal update software function to update PyDev with the URL http://pydev.sourceforge.net/updates/. To look further into PyDev, look here.

Apple's supplied python is quite old – my tiger install has 2.3.5. This may not be a problem for you, but you would be missing out on a lot. Also, there is a risk that Apple will update it. I'm not sure if moving from 2.3.5 to (say) 2.4 would cause code to break, but I guess it's possible. This happened to perl people recently: http://developers.slashdot.org/article.pl?sid=09/02/18/1435227
Macpython is a framework build (as is Apple's, I believe). To be honest, I'm not sure exactly what that means, but it's a prerequisite for some modules, in particular wxPython. If you get python from macports or fink, you will not be able to run wxPython (unless you run it through X11).

And guess what was forgotten by every answer here ... ActivePython.
No compilation required, even for third-party modules such as numpy, lxml, pyqt and thousands of others.

I recommend python (any python?) plus the ipython shell. My most recent experience with MacPython was MacPython 2.5, and I found IDLE frustrating to use as an editor. It's not very featureful, and its' very slow to scroll large quantities of output.

What version of Python (2.4, 2.5, 2.6, 3.0) do you standardize on for production development efforts (and why)?

In our group we primarily do search engine architecture and content integration work and most of that code base is in Python. All our build tools and Python module dependencies are in source control so they can be checked out and the environment loaded for use regardless of os/platform, kinda similar to the approach virtualenv uses.
For years we've maintained a code base compatible with Python 2.3 because one of the commercial products we use depends on Python 2.3. Over the years this has caused more and more issues as newer tools and libraries need newer versions of Python since 2.3 came out in ~2004.
We've recently decoupled our build environment from dependencies on the commercial product's environment and can use any version of Python (or Java) we want. Its been about a month or so since we standardized on Python 2.6 as the newest version of Python that is backwards compatible with previous versions.
Python 3.0 is not an option (for now) since we'd have to migrate too much of our code base to make our build and integration tools to work correctly again.
We like many of the new features of Python 2.6, especially the improved modules and things like class decorators, but many modules we depend on cause the Python 2.6 interpreter to spout various depreciation warnings. Another tool we're interested in for managing EC2 cloud cluster nodes, Supervisor doesn't even work correctly with Python 2.6.
Now I am wondering if we should standardize on Python 2.5 for now instead of using Python 2.6 in development of production environment tools. Most of the tools we want/need seem to work correctly with Python 2.5. We're trying to sort this out now before there are many dependencies on Python 2.6 features or modules.
Many Thanks!
-Michael

I wouldn't abandon 2.6 just because of deprecation warnings; those will disappear over time. (You can use the -W ignore option to the Python interpreter to prevent them from being printed out, at least) But if modules you need to use actually don't work with Python 2.6, that would be a legitimate reason to stay with 2.5. Python 2.5 is in wide use now and probably will be for a long time to come (consider how long 2.3 has lasted!), so even if you go with 2.5, you won't be forced to upgrade for a while.
I use Python 2.5 for all my development work, but only because it's the version that happens to be available in Gentoo (Linux)'s package repository. When the Gentoo maintainers declare Python 2.6 "stable"*, I'll switch to that. Of course, this reasoning wouldn't necessarily apply to you.
* Python 2.6 actually is stable, the reason it's not declared as such in Gentoo is that Gentoo relies on other programs which themselves depend on Python and are not yet upgraded to work with 2.6. Again, this reasoning probably doesn't apply to you.

My company is standardized in 2.5. Like you we can't make the switch to 3.0 for a million reasons, but I very much wish we could move up to 2.6.
Doing coding day to day I'll be looking through the documentation and I'll find exactly the module or function that I want, but then it'll have the little annotation: New in Version 2.6
I would say go with the newest version, and if you have depreciation warnings pop up (there will probably be very few) then just go in a find a better way to do it. Overall your code will be better with 2.6.

To me the most important to stick with python 2.5+ is because it officially supports ctypes, which changed many plugin systems.
Although you can find ctypes to work with 2.3/2.4, they are not officially bundled.
So my suggestion would be 2.5.

We're sticking with 2.5.2 for now. Our tech stack centers on Django (but we have a dozen other bits and bobs.) So we stay close to what they do.
We had to go back to docutils to 0.4 so it would work with epydoc 3.0.1. So far, this hasn't been a big issue, but it may -- at some point -- cause us to rethink our use of epydoc.
The 2.6 upgrade is part of our development plan. We have budget, but not fixed schedule right now.
The 3.0 upgrade, similarly, is something I remind folks of. We have to budget for it. We won't do it this year unless Django leaps to 3.0. We might do it next year.

I think the best solution is to give up the hope on total uniformity, although having a common environment is something to strive for. You will always will be confronted with version problems, for example when upgrading to the next best interpreter version.
So instead of dealing with it on a per issue base you could solve this problem by taking a good look on your release management.
Instead of releasing source, go for platform depending binaries (besides the source distribution).
So what you do is that you define a number of supported CPU's, for example:
x86-32, x86-64, sparc
Then which operating systems:
Linux, Windows, Solaris, FreeBSD
For each OS you support a number of their major versions.
Next step is that you provide binaries for all of them.
Yes indeed this will require quite some infrastructure investment and setting up of automatic building from your repositories (you do have them?).
The advantages is that your users only have 'one' thing to install and you can easily switch versions or even mixing versions. Actually you can even use different programming languages with this approach without affecting your release management too much.