What are the best practices for type hinting in Python?

What are the best practices for type hinting in Python?

Type hinting in Python enhances code readability and helps with static type checking. Best practices include using the Optional type for nullable values, specifying types for function parameters and return values, and using List, Dict, and other collection types from the typing module.

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

Sure! Here's a simple example:

from typing import List

def greet_users(names: List[str]) -> None:
    for name in names:
        print(f'Hello, {name}!')

This function takes a list of strings as input and returns nothing.

What if I want to use type hints with custom classes?

You can use type hints with custom classes by specifying the class name as the type. For example:

class User:
    def __init__(self, name: str, age: int):
        self.name = name
        self.age = age

def get_user_info(user: User) -> str:
    return f'{user.name} is {user.age} years old.'

Are there any tools to help with type checking?

Yes, tools like mypy can be used to perform static type checking in Python. You can run it on your codebase to catch type errors before runtime.