Python · Type Annotations

Before the x: type annotation syntax existed, how were type hints written so they'd be ignored at runtime but still readable by tools?

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More in Type Annotations

What does this print, and does it raise? ``` def repeat(s: str, n: int) -> str: return s * n print(repeat(["P"], 3)) ```

True or false: adding type annotations makes Python check the argument types when a function is called, raising an error on a mismatch.

What is the correct syntax to annotate a function's parameters AND its return type?

Does Optional[int] mean the argument is optional (can be omitted)?

What is Optional[X] equivalent to, written as a plain union?

How do you annotate a variable (with and without assigning a value)?

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