An amazing summer of code working on distutils2

The Google Summer of Code I've spent working on distutils2 is over. It was a really amazing experience, for many reasons.

First of all, we had a very good team, we were 5 students working on distutils2: Zubin, Éric, Josip, Konrad and me. In addition, Mouad have worked on the PyPI testing infrastructure. You could find what each person have done on the wiki page of distutils2.

We were in contact with each others really often, helping us when possible (in #distutils), and were continuously aware of the state of the work of each participant. This, in my opinion, have bring us in a good shape.

Then, I've learned a lot. Python packaging was completely new to me at the time of the GSoC start, and I was pretty unfamiliar with python good practices too, as I've been introducing myself to python in the late 2009.

I've recently looked at some python code I wrote just three months ago, and I was amazed to think about many improvements to made on it. I guess this is a good indicator of the path I've traveled since I wrote it.

This summer was awesome because I've learned about python good practices, now having some strong mercurial knowledge, and I've seen a little how the python community works.

Then, I would like to say a big thanks to all the mentors that have hanged around while needed, on IRC or via mail, and especially my mentor for this summer, Tarek Ziadé.

Thanks a lot for your motivation, your leadership and your cheerfulness, even with a new-born and a new work!

Why ?

I wanted to work on python packaging because, as the time pass, we were having a sort of complex tools in this field. Each one wanted to add features to distutils, but not in a standard way.

Now, we have PEPs that describes some format we agreed on (see PEP 345), and we wanted to have a tool on which users can base their code on, that's distutils2.

My job

I had to provide a way to crawl the PyPI indexes in a simple way, and do some installation / uninstallation scripts.

All the work done is available in my bitbucket repository.

Crawling the PyPI indexes

There are two ways of requesting informations from the indexes: using the "simple" index, that is a kind of REST index, and using XML-RPC.

I've done the two implementations, and a high level API to query those twos. Basically, this supports the mirroring infrastructure defined in PEP 381. So far, the work I've done is gonna be used in pip (they've basically copy/paste the code, but this will change as soon as we get something completely stable for distutils2), and that's a good news, as it was the main reason for what I've done that.

I've tried to have an unified API for the clients, to switch from one to another implementation easily. I'm already thinking of adding others crawlers to this stuff, and it was made to be extensible.

If you want to get more informations about the crawlers/PyPI clients, please refer to the distutils2 documentation, especially the pages about indexes.

You can find the changes I made about this in the distutils2 source code .

Installation / Uninstallation scripts

Next step was to think about an installation script, and an uninstaller. I've not done the uninstaller part, and it's a smart part, as it's basically removing some files from the system, so I'll probably do it in a near future.

distutils2 provides a way to install distributions, and to handle dependencies between releases. For now, this support is only about the last version of the METADATA (1.2) (See, the PEP 345), but I'm working on a compatibility layer for the old metadata, and for the informations provided via PIP requires.txt, for instance.

Extra work

Also, I've done some extra work. this includes:

  • working on the PEP 345, and having some discussion about it (about the names of some fields).
  • writing a PyPI server mock, useful for tests. you can find more information about it on the documentation.

Futures plans

As I said, I've enjoyed working on distutils2, and the people I've met here are really pleasant to work with. So I want to continue contributing on python, and especially on python packaging, because there is still a lot of things to do in this scope, to get something really usable.

I'm not plainly satisfied by the work I've done, so I'll probably tweak it a bit: the installer part is not yet completely finished, and I want to add support for a real REST index in the future.

We'll talk again of this in the next months, probably, but we definitely need a real REST API for PyPI, as the "simple" index is an ugly hack, in my opinion. I'll work on a serious proposition about this, maybe involving CouchDB, as it seems to be a good option for what we want here.

Issues

I've encountered some issues during this summer. The main one is that's hard to work remotely, especially being in the same room that we live, with others. I like to just think about a project with other people, a paper and a pencil, no computers. This have been not so possible at the start of the project, as I needed to read a lot of code to understand the codebase, and then to read/write emails.

I've finally managed to work in an office, so good point for home/office separation.

I'd not planned there will be so a high number of emails to read, in order to follow what's up in the python world, and be a part of the community seems to takes some times to read/write emails, especially for those (like me) that arent so confortable with english (but this had brought me some english fu !).

Thanks !

A big thanks to Graine Libre and Makina Corpus, which has offered me to come into their offices from time to time, to share they cheerfulness ! Many thanks too to the Google Summer of Code program for setting up such an initiative. If you're a student, if you're interested about FOSS, dont hesitate any second, it's a really good opportunity to work on interesting projects!