All I'm showing right now is that the Python code works. And that's exactly what generic types are: defining your return type based on the input type. Bug. "You don't really care for IS-A -- you really only care for BEHAVES-LIKE-A-(in-this-specific-context), so, if you do test, this behaviour is what you should be testing for.". distinction between an unannotated variable and a type alias is implicit, mypy default does not detect missing function arguments, only works Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Mypy error while calling functions dynamically, How Intuit democratizes AI development across teams through reusability. It acts as a linter, that allows you to write statically typed code, and verify the soundness of your types. I can always mark those lines as ignored, but I'd rather be able to test that the patch is compatible with the underlying method with mypy. To learn more, see our tips on writing great answers. MyPy not reporting issues on trivial code #8116 - GitHub Tuples are different from other collections, as they are essentially a way to represent a collection of data points related to an entity, kinda similar to how a C struct is stored in memory. These are all defined in the typing module that comes built-in with Python, and there's one thing that all of these have in common: they're generic. python - Mypy error while calling functions dynamically - Stack Overflow It's not like TypeScript, which needs to be compiled before it can work. mypy error: 113: error: "Message" not callable You signed in with another tab or window. By clicking Sign up for GitHub, you agree to our terms of service and test.py:6: note: 'reveal_type' always outputs 'Any' in unchecked functions. Trying to fix this with annotations results in what may be a more revealing error? Type declarations inside a function or class don't actually define the variable, but they add the type annotation to that function or class' metadata, in the form of a dictionary entry, into x.__annotations__. While we could keep this open as a usability issue, in that case I'd rather have a fresh issue that tackles the desired feature head on: enable --check-untyped-defs by default.