What are some examples of type annotations in Python?

What are some examples of type annotations in Python?

Type annotations in Python are a way 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.
3. def get_user_info() -> Tuple[str, int]: - This function returns a tuple containing a string and an integer.

Can you explain the benefits of using type annotations?

Sure! Type annotations help with code readability, enable better error checking, and improve IDE support for autocompletion and type hints.

Are there any limitations to using type annotations?

Yes, type annotations are optional in Python, so they don't enforce type checking at runtime. They also require additional effort to maintain.

Can you show me a more complex example?

Certainly! Here's a more complex example:

from typing import List, Dict

def process_data(data: List[Dict[str, int]]) -> None:
    for item in data:
        print(item['value'])

This function takes a list of dictionaries with string keys and integer values.