Friday, March 07, 2008

Pylons: first impressions

A couple co-workers and I spent some time with Pylons yesterday, enough to get to where we started to feel productive, but not much more than that. I think there's value in a newbie's first impressions, so here are mine. I'm sure at least some of these are wrong.
  1. Poor documentation of core Pylons (Mako and SQLAlchemy are fine -- thanks, Mike). I had to use the source several times. I'm still not really sure how Routes works, although I was mostly able to make it do what I wanted. The first tutorial overcomplicated things, showing how to configure things to handle semi-obscure requirements, without explaining those requirements or simpler alternatives.
  2. Helpful community. I got most of the answers I needed pretty quickly in the #pylons freenode IRC channel.
  3. Not much black magic: if you know Python you won't be struggling with weird Pylons-only concepts. It's all modules, classes, and dicts put together in an intuitive way (at least to my way of thinking).
  4. SA (SQLAlchemy) is an amazing pleasure to use. (Okay, not just in Pylons, but I had to say it.) I have a slightly unusual schema -- the details are outside my scope here -- and SA's autoload handled it perfectly.
  5. I wrote more CRUD boilerplate than I would have liked. There is no real alternative to Django's "admin app." DBMechanic looks like it's getting close, but it's TG-and-Genshi only for now. FormAlchemy is a partial solution (I did use it) but only does html generation; you'll still write boilerplate in your controllers.
  6. Genshi appeals to me in theory but in practice its XML nature makes it feel clunky. XInclude as an alternative to template inheritance? 3 lines of xmlns per template? Mako has its own verbosity problems, e.g., having to do a def to pass a title to the parent template, but these aren't inherent to Mako's approach the way they are to Genshi's (we're XML, dammit), and Mike seems mildy interested in improving this specific example for the next release.
  7. The pyfacebook tutorial is long on throwing wads of code at you and short on explaining what's actually going on. What does facebook.check_session() do? What does the facebook_middleware do? Why? Most facebook api tutorials have this same problem. Obviously I haven't written a better one, so call me a hypocrite, but tutorial authors, please explain the why and not just the what.


jacob said...

You mentioned django, what is the benefit to pylons vs django?

I am considering which 'framework' to jump in bed with, looking for input.


Jonathan Ellis said...

From my perspective, the main reason to use Pylons is that it's designed to work well with SQLAlchemy and Mako/Genshi, which are much better than the django ORM and templating engine.

DJW said...

Thanks for the heads up, I'm just working my way up in python (system/shell scripts, sqlalchemy, and now web work) with a background in PHP and some experience w/Rails.

I generally dev on windows, so Pylons won the toss up because Zope didn't like my machine and I was in the mood to compile it ( just to find out if I like it or not)

John Brennan said...

I just stumbled on to your blog. I've been using Pylons for several months now and love it. Although PHP is still in my heart and I've been working in parallel with CakePHP which is another MVC.

Getting started with Pylons is pretty quick, but because it is so flexible, I found it hard to really make it my own. What I mean by that is adding authentication, building out the mako templates, etc.

After several discussions with the great fellows over at the pylons google group, I decided to put all my code online.

It's over at:
Zero to 60 with Pylons... in just minutes.