Message 230396 - Python tracker
--> s = [] --> s += 1 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'int' object is not iterable For comparison, when NotImplemented is appropriately returned the message looks like this: --> s -= 1 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for -=: 'list' and 'int' Which is certainly more helpful than "<blank> object is not iterable"