Python mypy warning of incompatible type when using Enum Flag Question: I am trying to make a variable that can be from a set of enum values, and then select a specific one when using it elsewhere. from enum import Flag, auto class MyEnum(Flag): FOO: int = auto() BAR: int = auto() MOO: int = …
Why does mypy complain about my dictionary comprehension? Question: I’m trying to do an update of a dictionary with a dictionary comprehension. My code works fine, but mypy raises an error while parsing the types. Here’s the code: load_result = {"load_code": "something"} load_result.update({ quality_result.quality_code: [quality_result.quantity] for quality_result in random_quality_results() }) In that code the quality_result …
Mypy error on __init_subclass__ example from python documentation Question: From the official Python 3 documentation for __init__subclass__: class Philosopher: def __init_subclass__(cls, /, default_name: str, **kwargs): super().__init_subclass__(**kwargs) cls.default_name = default_name class AustralianPhilosopher(Philosopher, default_name="Bruce"): pass The problem is, mypy raises "Type[Philosopher]" has no attribute "default_name". What is the solution for this? How can I make mypy take …
Python typing for a metaclass Singleton Question: I have a Python (3.8) metaclass for a singleton as seen here I’ve tried to add typings like so: from typing import Dict, Any, TypeVar, Type _T = TypeVar("_T", bound="Singleton") class Singleton(type): _instances: Dict[Any, _T] = {} def __call__(cls: Type[_T], *args: Any, **kwargs: Any) -> _T: if cls …
Type hint for numpy.ndarray containing unsignedinteger Question: I have a numpy array that contains unsignedinteger, something like this: arr = np.uint16([5, 100, 2000]) array([ 5, 100, 2000], dtype=uint16) This arr will be input to a function. I am wondering how the type hint of the function argument should look like? def myfunc(arr: ?): pass I …
Python type hints for unpacking object Question: I’m trying to implement type hinting for object unpacking. Here is what I have currently from typing import Tuple class A: def __init__(self, x: int, y: str): self.x = x self.y = y def astuple(self) -> Tuple[int, str]: return self.x, self.y # Need to annotate the return type …
Type checking a method call with a default argument prior to keyword argument dictionary Question: Given def f_with_opt(opt_arg: bool | None = None, **kwargs): print(f"{opt_arg=}, {kwargs=}") def function() -> None: kwargs = {"foo": "bar"} f_with_opt(**kwargs) # mypy complains about this line if __name__ == "__main__": function() mypy reports test.py:7:18: error: Argument 1 to "f_with_opt" has …
Ignoring mypy attr-defined with triple quotes Question: The following code: # type: ignore[attr-defined] timeit.template = """ # type: ignore[attr-defined] def inner(_it, _timer{init}): {setup} _t0 = _timer() for _i in _it: retval = {stmt} _t1 = _timer() return _t1 – _t0, retval """ # type: ignore[attr-defined] # type: ignore[attr-defined] Yields error: src/snncompare/Experiment_runner.py:45: error: Module has no …
mypy: error: Module "multiprocessing.managers" has no attribute "EventProxy" [attr-defined] Question: I have a method which takes a multiprocessing.Manager().Event(), for the purposes of gracefully stopping my app. When I run mypy against it, it complains that it’s not a valid type: error: Module "multiprocessing.managers" has no attribute "EventProxy" [attr-defined] Code: from multiprocessing.managers import EventProxy class App: …
mypy seems to think that (*args, **kwargs) could match to any funtion signature? Question: How does mypy apply the Liskov substitution principle to *args, **kwargs parameters? I thought the following code should fail a mypy check since some calls to f allowed by the Base class are not allowed by C, but it actually passed. …
