What are Python type annotations and how do I use them?

What are Python type annotations and how do I use them?

Python type annotations are a way to indicate the expected data types of variables, function parameters, and return values. They help with code readability and can be checked by static type checkers.

Can you give me an example of how to use type annotations in a function?

Sure! Here's a simple example:

def add_numbers(a: int, b: int) -> int:
    return a + b

In this function, a and b are expected to be integers, and the function returns an integer.

Are type annotations mandatory in Python?

No, type annotations are optional in Python. You can write code without them, but using them can improve code clarity and help with debugging.

What tools can I use to check type annotations?

You can use tools like mypy, pyright, or built-in IDE features in editors like PyCharm or VSCode to check type annotations.