Github, Setuptools, and What I Learned Today

How’s that for a title? I just have to say, git is pretty awesome, but I’m assuming you knew that. I read an article today where (for the first time I’ve seen) someone was making a case for bazaar over git. I used bazaar for our development team for almost two years, it was my “upgrade” to “distributed” over subversion. Sorry, can’t find the article. In a nutshell, 20 out of dvcs users [on that webpage] prefer git over bzr. Maybe corn flakes too…

tldr;

Click the little ‘X’ in the upper-right corner…

good, bad, indifferent

I’m not really going to argue points about the two systems today, all I’ll say is that I’m totally digging git. And my motivation is several-fold:

  • Video - Summary: Linus Torvalds tells Google staff how stupid they are ‘coz they don’t use git… over and over and over again.
  • Like, the internets use github, both of them, duhh
  • I get to use it at work :)

Further rationale

Bazaar was great, don’t get me wrong, but some of my newest most favorite features are (in no particular order):

  • On-the-fly branching! How cool is that?? In bzr (or svn) a branch would require a different folder. In-place branches are wicked.
  • Submodules Is there another system where this actually works?
  • Rebase OMFG nuff said.

There’s more, but that’s on the top of my list right now.

mixin(setuptools)

One of the neat things about settling in with a new development team is the things that I learn. At the top of my list are:

  • the things I’ve been doing right,
  • the things I’ve been doing wrong.

Of the latter, the first that comes to mind is setuptools. I’ve been managing Python dependencies manually for the last several years, in my mind, somehow, convinced that efficient dependency management in Python was somehow flawed, or “seldom agreed upon”. Probably a result of me being in a hurry most of the time.

Thankfully, I’ve seen the light! A colleague at work turned me back on to virtualenv, and I now realize what I’ve been missing in python all along: a reliable, simple deployment strategy. I’ll have to write more on that workflow later.

mixin(git)

This part is my favorite: without too much trouble, you can configure setuptools to pull from a github repo (or probably any other repo). There are only two criteria:

  • The remote project must be setuptools-compatible
  • The endpoint must provide a tarball (equivalent to an .egg)

In the setup.py you only need specify the tarball location in a specific way in the dependency_links kwarg.

Eg:

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from setuptools import setup
#other stuff here
...
setup(
name = "my-project",
version = "1.0.0",
author = "Aaron Fay",
author_email = "me@gmail.com",
description = ("Simple python setuptools package."),
license = "BSD",
keywords = "example python package setuptools",
url = "http://my.url",
packages = ['an_example_pypi_project',],
long_description = "My description"
install_requires = [
'my_other_package==1.0.0' ## look here!
],
dependency_links = [
'https://github.com/AaronFay/my-other-package/tarball/master#egg=my_other_package-1.0.0'
]
)

The trick in all this is the #egg=my_other_package-1.0.0 part, setuptools will recognize the package name and match it up with a required package in install_requires. It even has a pretty smart way to differentiate package versions.

wrapping up

Without too much trouble, a very efficient development/production workflow can be set up with the combination of virtualenv, git, and setuptools. It’s definitely an exciting time to be in software development.

Until next time.

af