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Testing & modern typing

pytest basics, mocks, type hints, TypedDict, Protocol, and static-checking patterns.

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How to use Optional type hint in Python

Use the Optional type hint to indicate a parameter can be a string or None, with an example function that handles both cases.

typing optional type-hints
Python 
from typing import Optional

def greet(name: Optional[str]) -> str:
    if name is None:
        return "Hello, anonymous!"
    else:
        return f"Hello, {name}!"

if __name__ == "__main__":
    print(greet("Alice"))
    print(greet(None))
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