The typing module provides a function get_args which retrieves the arguments with which your Literal was initialized. >>> from typing import Literal, get_args >>> l = Literal[‘add’, ‘mul’] >>> get_args(l) (‘add’, ‘mul’) However, I don’t think you gain anything by using a Literal for what you propose.
Referencing ECMA-335, the is operator generates the isinst object model IL instruction (Partition III §4.6), which is part of the base instruction set as opposed to being part of the Reflection library (Partition IV §5.5). Edit: The is operator is extremely efficient compared to the reflection library. You could perform basically the same test much … Read more
Ruby is “strong typed“. Strong typing means an object’s type (not in the OOP sense, but in a general sense) is checked before an operation requiring a certain type is executed on it. Weak typed means that no checking is done to ensure that the operation can succeed on the object. (For example, when a … Read more
typing.Callable is the type you use to indicate a callable. Most python types that support the () operator are of the type collections.abc.Callable. Examples include functions, classmethods, staticmethods, bound methods and lambdas. In summary, anything with a __call__ method (which is how () is implemented), is a callable. PEP 677 attempted to introduce implicit tuple-with-arrow … Read more
I assume that typical path objects are either Paths or strs, as such you could use a Union. In addition, the more inclusive os.PathLike is preferred over pathlib.Path. Python 3.10 or newer: import os def read_json(path: str | os.PathLike): … Python 3.5 – 3.9: import os import typing def read_json(path: typing.Union[str, os.PathLike]): …
According to PEP 589 you can use alternative syntax to create a TypedDict as follows: Movie = TypedDict(‘Movie’, {‘name’: str, ‘year’: int}) So, in your case, you could write: from typing import TypedDict RandomAlphabet = TypedDict(‘RandomAlphabet’, {‘A(2)’: str}) or for the second example: RandomAlphabet = TypedDict(‘RandomAlphabet’, {‘return’: str}) PEP 589 warns, though: This syntax doesn’t … Read more
Use square brackets: Tuple[pd.DataFrame, pd.DataFrame] From the docs: Tuple type; Tuple[X, Y] is the type of a tuple of two items with the first item of type X and the second of type Y. The type of the empty tuple can be written as Tuple[()]. EDIT: With the release of python 3.9, you can now … Read more
To do that you need to extract props interface from children component (and preferably also parent) and use it this way: interface ParentProps { children: ReactElement<ChildrenProps> | Array<ReactElement<ChildrenProps>>; } so in your case it would look like this: interface IMenu { children: ReactElement<IMenuItem> | Array<ReactElement<IMenuItem>>; } const MenuItem: React.FunctionComponent<IMenuItem> = ({ props }) => { … Read more
NoReturn means the function never returns a value. The function either does not terminate or always throws an exception: “The typing module provides a special type NoReturn to annotate functions that never return normally. For example, a function that unconditionally raises an exception..”. from typing import NoReturn def stop() -> NoReturn: raise RuntimeError(‘no way’) That … Read more
Both approaches are valid. If your function uses conditional types in the return it will need to use type assertions, as typescript will not try to reason about the conditional type since it contains a free type parameter: function dependsOnParameter<B extends boolean>(x: B): B extends true ? number : string { if (x) { return … Read more