What are Python annotations in version 3.9?

What are Python annotations in version 3.9?

Python annotations are a way to attach metadata to function arguments and return values. In version 3.9, they are more flexible and can include types, which helps with type checking and code readability.

Can you give me an example of how to use annotations?

Sure! Here's a simple example:

def greet(name: str) -> str:
    return f'Hello, {name}!'

In this function, name is annotated as a string, and the function returns a string.

What are the benefits of using annotations?

Annotations improve code clarity, enable better static type checking, and help IDEs provide better autocompletion and error detection.

Are there any limitations to using annotations?

Yes, annotations are not enforced at runtime, so they are mainly for documentation and type hinting purposes. They don't affect the actual behavior of the code.