mutmut VS MonkeyType

I wrote one (https://github.com/boxed/scientist) as I found the existing ones very complicated and that just gives me a bad feeling. Since I'm the author of mutmut (https://github.com/boxed/mutmut), I also made sure my implementation was 100% mutation tested before I used it in production.

I used my implementation to replace number parsing in my work project: https://kodare.net/2021/04/04/safe_number_parsing.html

Mutmut introduces a clever approach to scrutinizing your tests. It evaluates the effectiveness of your test suite by slightly altering the code after the tests have been written. If a test fails after a minor change, that's a good sign; it means the test is robust enough to catch those changes. But if the test passes even after the code change, it indicates that the test isn't effectively detecting that alteration – this is what Mutmut terms a "surviving mutant."

mutmut for mutation testing.

i can't, unfortunately, it was youtube internal code. but by the same token a lot of the performance stuff was specific optimisations for that code and would not really generalise.

one of the current "extremely large python codebase" projects is instagram, and they do have some public repos, notably monkeytype (https://github.com/Instagram/MonkeyType) which youtube did have its own analogue of, and cinder (https://engineering.fb.com/2022/05/02/open-source/cinder-jit...). in general facebook's engineering blog is a great place to read about this sort of thing.

MonkeyType collects runtime types of function arguments and return values, and can automatically generate stub files or add type annotations directly to your Python code based on the types collected at runtime.

To alleviate the burden of manual annotation, MonkeyType offers a clever solution. It dynamically observes the types entering and leaving functions during code execution. Based on this observation, it generates a preliminary draft of type annotations. This significantly reduces the effort needed to add type hints to legacy code.

https://github.com/instagram/MonkeyType can perform the call logging, and can export a static typing file which is used by mypy, but also e.g. PyCharm. It doesn't expose such fine grained types, but you could build that based on the logged data.

Which introduces MonkeyType, a python library that generatics static type annotations by collecting runtime types.

Not sure if you're joking but there is something similar for python developed by a rather well known company https://github.com/Instagram/MonkeyType