Python Type Challenge - Level: extreme, Topic: concatenate

Challenge - concatenate

3.12.7

type checker: pyright

Complete code following the instructions, so that lines followed by # expect-type-error (if any) fail type check, while others can pass.
Hit the "▶️ Run" button to see result.

💡 Read Hints

Check out Concatenate
Omit the return type if you struggle with it

Open Pyright Playground

Stuck? Check out solution

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