What are some examples of type annotations in Python?

What are some examples of type annotations in Python?

Type annotations in Python are used to indicate the expected data types of variables. For example:

1. def add(a: int, b: int) -> int: - This function takes two integers and returns an integer.
2. def greet(name: str) -> None: - This function takes a string and returns nothing.

Can you show me more complex examples?

Sure! Here are a couple of more complex examples:

1. def process_data(data: List[Dict[str, Union[int, str]]]) -> None: - This function takes a list of dictionaries with string keys and values that can be either integers or strings.
2. def fetch_user(user_id: int) -> Optional[User]: - This function returns a User object or None if the user is not found.

What are the benefits of using type annotations?

Type annotations help with code readability, enable better tooling support (like IDEs), and can catch type-related errors during development.