What are some advanced type hints in Python?

What are some advanced type hints in Python?

Advanced type hints in Python include features like TypeVar, Union, Optional, and Callable. Would you like examples of each?

Yes, please provide examples for TypeVar and Union.

Sure! TypeVar allows you to create generic types. For example: T = TypeVar('T') can be used in functions to indicate that the function can accept any type. Union, on the other hand, is used to specify that a value can be one of several types. For example: Union[int, str] means the value can be either an integer or a string.

How about Optional? Can you explain that?

Absolutely! Optional is a shorthand for Union with None. For instance, Optional[str] is equivalent to Union[str, None], meaning the value can be a string or None.

What about Callable? How is it used?

Callable is used to indicate that a variable is a function. For example, Callable[[int, int], int] means a function that takes two integers and returns an integer.