Use float only, as int is implied in that type: def my_func(number: float): PEP 484 Type Hints specifically states that: Rather than requiring that users write import numbers and then use numbers.Float etc., this PEP proposes a straightforward shortcut that is almost as effective: when an argument is annotated as having type float, an argument … Read more
Type hinting the Color class should work: def get_color_return_something(some_color: Color): print(some_color.value)
See the fifth paragraph of the abstract in the PEP you link to: While these annotations are available at runtime through the usual __annotations__ attribute, no type checking happens at runtime . Instead, the proposal assumes the existence of a separate off-line type checker which users can run over their source code voluntarily
You have a forward declaration; functions (to be bound as methods) are created before the class is, so the name Vector doesn’t yet exist. Only when all of the class body has been executed, can Python create the class object and bind the name Vector to it. Simply use a string with the name instead: … Read more
There is no real difference between using a plain typing.Dict and dict, no. However, typing.Dict is a Generic type * that lets you specify the type of the keys and values too, making it more flexible: def change_bandwidths(new_bandwidths: typing.Dict[str, str], user_id: int, user_name: str) -> bool: As such, it could well be that at some … Read more
and types.ModuleType() is a constructor. That doesn’t matter. types.ModuleType is still a reference to a type, just like str and int are. There is no need for a generic Module[typehint] annotation, so types.ModuleType is exacly what you need to use here. For example, the official Python typeshed project provides a type hint annotation for sys.modules … Read more
No. Omitting Optional was previously allowed, but has since been removed. A past version of this PEP allowed type checkers to assume an optional type when the default value is None […] This is no longer the recommended behavior. Type checkers should move towards requiring the optional type to be made explicit. Some tools may … Read more
Update Check recent numpy versions for a new typing module https://numpy.org/doc/stable/reference/typing.html#module-numpy.typing dated answer It looks like typing module was developed at: https://github.com/python/typing The main numpy repository is at https://github.com/numpy/numpy Python bugs and commits can be tracked at http://bugs.python.org/ The usual way of adding a feature is to fork the main repository, develop the feature till … Read more
Python type hinting can’t exclude types. You can’t exclude Nones, strs or any another type. The only thing you can use to try to emulate None exclusion is to use Union and write every type you are actually using in the dictionary.
T‘s type must be consistent across multiple uses within a given scope, while U‘s does not. With a Union type used as function parameters, the arguments as well as the return type can all be different: U = Union[int, str] def union_f(arg1: U, arg2: U) -> U: return arg1 x = union_f(1, “b”) # No … Read more