by Dan Crosta
Very occasionally, I write code where I'm given an object of some class (usually from a library call), but I wish to use additional methods on that class as though they had been defined there. In some languages (Objective-C shines in this regard with categories), you can do this very naturally. In Python, most people probably resort to monkey patching to accomplish this.
Inspired by David Beazley's Keynote at PyCon, I've been digging around in code objects in Python lately. I don't have a particular axe to grind, nor some particular task to solve (yet?), so consider this post just some notes and ramblings that might be of interest (and my apologies if not).
Disclaimer: This post is about CPython version 2.7, though much of it is also likely true for other CPython versions (including 3.x). I make no claims to its accuracy or applicability to PyPy, Jython, IronPython, etc.
What's your new year's resolution? One of mine is to be more active in helping and mentoring new Pythonistas, which is why I wrote the twitter bot behind @PythonQuestions. Inspired by the @MongoQuestion twitter bot, @PythonQuestions tweets new Stack Overflow questions tagged "Python".
I first heard about The Hitchhiker's Guide to Python at PyCodeConf a few months ago. It's a fantastic idea: open source, community-driven documentation on how to do Python right: everything from how to learn Python, to how to write idiomatic code, to how to distribute your projects, to surveys of best-of-breed open source projects and libraries you can build projects and applications on top of. Many many thanks to Kenneth Reitz for creating and maintaining the project, which is hosted at GitHub.
At this time, the Hitchhiker's guide is a little rough around the edges: many sections are only outlined, and need content written; other sections may not even exist yet. We can safely consider it a first draft, or, if you prefer, an alpha.
This sort of undertaking is effectively impossible for one person to maintain--one person can't possibly know of every project, library, and idiom. Moreover, it's unfair as a user of the Guide to demand that one person must do all the work.
Therefore, a call to action: in order to make the Python community great, everyone should fork the Hitchhiker's Guide today, find (or add) a section of interest, and submit a pull request. If you're lucky, Kenneth will give you a sparkly cake.
And a pledge: time allowing (for, sadly, contributing to Python documentation is not my day job), I will make one contribution to the Hitchhiker's Guide per week until it reaches completion, or until there's nothing left to which I can conscientiously contribute (I won't attempt to document things which I know too little about).
Finally, since this is a community effort, I want to give a shout-out to all those who've contributed to the Guide so far:
Thanks to everyone who's helping to make Python a better place!
(To the folks above, if you'd like me to add or correct any of the contact information, please leave a comment.)
Yaniv Aknin (whose blog I found through Planet Python) recently blogged about his ZSH and virtualenv setup. As I was reading it, I recognized that he's solving some of the same problems I only recently solved myself (though through a very different approach than he took), so I figured I would share it, too.