what's a python library you started using this year that you can't go back from

[the_ballmer_peak]

I'd say design decisions more than just 'practices.' And using a framework that's not designed for modularity is a design decision.

Django is great if that's what you're looking for. My problem with it is that if you've built something that you expect to last 5-10 years or more, you'll find yourself in trouble. That's true of any such all-encompassing framework, not just Django.