What are optional types in Python and how do I use them?

What are optional types in Python and how do I use them?

Optional types in Python allow you to specify that a variable can either hold a value of a certain type or be None. You can use the Optional type from the typing module.

Can you give me an example of how to define a function with optional types?

Sure! Here's an example:

from typing import Optional

def greet(name: Optional[str] = None) -> str:
    if name is None:
        return 'Hello, Guest!'
    return f'Hello, {name}!'

What happens if I don't use Optional and just use a type?

If you don't use Optional, the function will expect a value of that type and will raise a TypeError if you pass None.

Are there any best practices for using optional types?

Yes, it's best to use optional types when a parameter can logically be absent. It improves code readability and helps with type checking.