I encourage every one to at least stop writing code in Python.
replies(5):
Use a type checker! Pyright can get you like 80% of Rust's type safety.
mypy's output is, AFAICT, also non-deterministic, and doesn't support a programmatic format that I know of. This makes it next to impossible to write a wrapper script to diff the errors to, for example, show only errors introduced by the change one is making.
Relying on my devs to manually trawl through 80k lines of errors for ones they might be adding in is a lost cause.
Our codebase also uses SQLAlchemy extensively, which does not play well with typecheckers. (There is an extension to aid in this, but it regrettably SIGSEGVs.)
Also this took me forever to understand:
from typing import Dict
JsonValue = str | Dict[str, "JsonValue"]
def foo() -> JsonValue:
x: Dict[str, str] = {"a": "b"}
return x
x: JsonValue = foo()
example.py:7: error: Incompatible return value type (got "dict[str, str]", expected "str | dict[str, JsonValue]") [return-value]