Comment by mekoka | Hacker News Reader

Comment by mekoka | Hacker News Reader

Very nice article and thanks for the intro to Requests. Though, I'm not sure we would agree about Django being the best thing to learn in the long run.

I undertook to move to Python for web development about 8 months ago and embarked on a thorough quest for the one true framework. Obviously Django was the first and most recurrent recommendation. Having briefly toyed with it in the past, I really could see myself commit to it for the long run. The various raving reviews also made the choice all that simple. I was all ready to give it my seal of approval, when I encountered my first complain, which was so compelling that it raised an eyebrow.

It was about an experienced Python programmer explaining that as time went and as he progressed with Django, he found himself increasingly swapping parts out of it for external libraries. SQLAlchemy, WTForms, Jinja2. In the end he had only the routing module and the admin, which wasn't that big a deal for him. He was asking what was the point of using a full-stack framework not necessarily designed with interchangeability in mind, if you end up just using it like a glue mini-framework?

As I dug deeper, I found more similar complains, all from similarly experienced developers, who all ended up adopting something else with a light plugable base approach. I heard of Repose.bfg, Pyramid, Werkzeug and a slew of other ones, that allow you to get down and dirty fast, while still allowing you to get big in the long run.

Just as you, I was recently asked by a friend wanting to get into web applications development to recommend a platform to work from. I also did point to Django, but explained that it wasn't because it's necessarily the best, but rather because it's the gentler introduction. It comes with batteries, crutches, first aid kit and a nice box of goodies, perfect for someone who has no clue what they're doing.

Note that I'm not dissing Django or relegating it as an amateurish framework. I agonized on my decision and still sometimes experience some Django envy (FYI I adopted Flask and don't regret it one bit). Nonetheless, it's hard to deny that it does a particularly good job of introducing newbies to good concepts fast, while at the same time being notorious for getting in the way of more experienced developer than some other frameworks.

The issue that I have with that attitude (as an experienced Python and Django developer) is that there's a lot more to it than just "swapping out Django's DB and replacing it with SQLAlchemy". You miss out on most of the infrastructure around Django's database stuff that makes it so easy and worthwhile to use.

For example, fixtures. In Django, you can include them in your tests and have it All Just Work(TM):

https://docs.djangoproject.com/en/dev/topics/testing/#fixtur...

You can also use them outside of testing, too:

https://docs.djangoproject.com/en/dev/howto/initial-data/#pr...

Fixtures in Flask/SQLAlchemy? Not so much - you have to roll your own (crappy) implementation:

http://farmdev.com/projects/fixture/using-fixture-with-pylon...

http://flask.pocoo.org/mailinglist/archive/2011/3/6/flask-sq...

Also note that, while I'm picking on fixtures here, Django also has a bunch of other database related features, like introspecting a pre-existing database, and generating a bunch of Model classes from it. Combine that with South and you're 90% of the way there when migrating the data from a legacy system.

This has turned into a bit of a rant, but I've seen a lot of half-baked reimplementations in "pluggable" architectures of stuff which Django just gets right.

It's not a matter of attitude, it's about having tools, evaluating them for what they're doing for you and making a choice. There's always a conscious trade-off.

You can't focus on what's good about Django, as if someone picking SQLAlchemy or Werkzeug is a fool at a loss. The same goes for the other libraries that I listed.

In my own case, I'm not particularly a fan of opinionated frameworks. I've had my share of griefs with them. Django looked nice, but I easily could identify with the pains those developers went through when dealing with its lack of flexibility at certain corners. I was new at Python, not at web development, I did not need the hand holding, no matter how nice and clever the code was.

This was not a one evening process, I read blog posts, forums, perused StackOverflow and even HN. It took weeks. Feel free to take the journey, then tell me it didn't give you pause.

Flask is a small framework that is far from pretending to be what Django is. It's not even at version 1, but with its flaws, I'm quite happy with what it's allowing me to do.

I don't mind you ranting about my post, just don't assume that I would use Django the way you do. Stuff that you relish might be what turns me off and the beauty of it all is that it's all acceptable.

I really don't understand the "lack of flexibility" thing myself. I've made Django and Django's ORM and admin do all sorts of weird stuff, and it's much easier to build on top of that than to reroll everything, which is what you have to do with Pylons/Flask/Bottle/...

And database/fixture set up is something that you will have to do, assuming that you test your app, and that your app is more sophisticated than "I have some strings which I want to upper case". Ditto for working with legacy databases, migrating data, bla bla blah.

The default option from what I've seen tends to be to set your DB up once and hope for the best, or else repopulate it after every test. Both of these options work great(ish) when you first start your project, but then grind you down six months later when your test suite takes an hour to run. A decent ORM, along with in-memory SQLite and fixture setup is generally what's settled on for most integration suites that I've seen, and Django does that out of the box.

Also - a minor nit, but WTForms and Jinja2 are based on Django's form and template libraries. Switching to them doesn't get you that much - they certainly don't replace any of Django's core infrastructure. And I've found SQLAlchemy to be basically unusable unless you use the new 'declarative base' stuff, which looks suspiciously similar to... Django's ORM :)

Your comment, in particular the part about SQLAlchemy, reads a lot like the blub programmer.

Ad-hominem much?

> And I've found SQLAlchemy to be basically unusable unless you use the new 'declarative base' stuff, which looks suspiciously similar to... Django's ORM :)

I can relieve your suspicions as I never looked at Django's ORM at all when designing declarative. It's merely poking normal SQLAlchemy attributes, all of which existed before Django was ever released, onto a class. I can assure you active-record style class mapping is not an idea Django invented.

The same design pressure (to make the simple stuff easier) is at work in both cases. Much like, say, Bottle and Flask looking very similar.

The "basically unusable" is probably a little harsh, but I've never really understood the motivation behind some of SQLAlchemy's design decisions. eg. separating one class/table definition into interacting table, model and mapping classes makes no sense at least 99% of the time - that seems like something which should be hidden internally (but accessible if you really need it).

well if you read our docs you'll see that they're entirely in agreement with that. separate mapping/table design is called "classical mapping" and was years ago superceded by the declarative style. Update your sqlalchemy knowledge before commenting on it.

interestingly enough a ton of users still prefer the mappers/tables to be separate.

Django is where the jobs are. If you want to profit from your skills, the smart bet is in learning technologies that are in demand.

I'd say the smart bet is in learning technologies that are relevant and to be comfortable with your tools. I don't recall the last time a client asked/cared what technology stack we're using. They usually just need stuff built.

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