# Errors 1 in [1, 2, 3] 1 in (1, 2, 3) 1 in ( 1, 2, 3 ) fruits = ["cherry", "grapes"] "cherry" in fruits _ = {key: value for key, value in {"a": 1, "b": 2}.items() if key in ("a", "b")} # OK fruits in [[1, 2, 3], [4, 5, 6]] fruits in [1, 2, 3] 1 in [[1, 2, 3], [4, 5, 6]] _ = {key: value for key, value in {"a": 1, "b": 2}.items() if key in (["a", "b"], ["c", "d"])}