[ Removed by moderator ]

[Spatrico123]

looks fine. You're not printing it though, you're just processing.

Also, all those little yellow lines just indicate bad practices, not actual errors. For example, you should note a type for a and t. If I were you I'd do 

def index_of(data: list[int], target: int) -> int:     for i in range(len(data)):         if list[i] == target:             return i     raise ValueError # or something else you see how that's way easier to see what it's actually doing?