This was Python's behavior until Python 2; `long`, the arbitrary-precision integer, was a separate type, and `int` arithmetic overflow caused a ValueError. One of the big changes in Python 2 was to imitate the behavior of Smalltalk and (most) Lisp by transparently overflowing `int` arithmetic to `long` instead of requiring an explicit `long()` cast. Python 3 eliminated the separate `long` type altogether.

Having been bitten by the Smalltalk behavior, I am skeptical that the Python 2 change was a good idea.