3 ms·

The classic bugs are passing the wrong type of argument and calling a method on None. PyCharm did static analysis and caught a lot of these, but it wasn't alwa

by pas 6y ago

The classic bugs are passing the wrong type of argument and calling a method on None. PyCharm did static analysis and caught a lot of these, but it wasn't always that obvious. With a type hint, it's easy for the IDE to spot things. It's easy to integrate mypy into the CI process, etc. We inherited a py2.7 codebase, written by one dev. It uses a library written also by that dev. We had absolutely no idea what worked how. Sure, looking at the code gave us a very rough big picture, but adding typing helps with the details.

matesz 6y ago
> We inherited a py2.7 codebase, written by one dev. It uses a library written also by that dev. We had absolutely no idea what worked how. Sure, looking at the code gave us a very rough big picture, but adding typing helps with the details. I see how this could be helpful for legacy codebase - add typings, run mypy and see if it breaks. Good point - thanks. How many lines of code that inherited codebase had btw?
- pas 6y ago
  Quite small in LOCs less than 10K. (A horribly non-idiomatic custom ETL lib, and a big ball of MVC stuff using pyramid and sqlalchemy/zope.transaction.)