What are the best practices for type annotation in Python?

What are the best practices for type annotation in Python?

Type annotations in Python enhance code readability and help with static type checking. Best practices include using clear and descriptive types, leveraging the Optional type for nullable values, and using Union for multiple possible types.

Can you give me an example of using type 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 about using type hints with collections?

Great question! You can use List, Dict, and other collection types from the typing module. For example:

from typing import List

def process_items(items: List[int]) -> None:
    for item in items:
        print(item)

Are there any tools to help with type checking?

Yes! Tools like mypy and pyright can analyze your code for type consistency and help catch errors before runtime.