Victor, if people want to use getrandbits(), we should backport the Python3 code, not reinvent it from scratch.

Note too Mark's comment:  "There are several places in the source where something of the form `int(i * random.random())` is used".  The `min()` trick is relatively easy to apply via simple, local editing of such places.  

Your "It doesn't handle negative numbers nor empty ranges" should be a hint about what a pain it is to rewrite everything wholesale to use a _fundamentally_ different method.