[hawski]

But it is incorrect. Positive or negative number divided by zero is either +infinity or -infinity. For a positive dividend it would be +infinity only if the divisor got there from a positive number towards absolute 0, but at the time of doing the division we only have absolute 0 as the divisor.

The usual floating point behavior of having signed zero (+0 and -0) is not enough for this to be correct. You would also need a normal proper unsigned absolute 0 as well. Then you could give +inf for division with +0 and -inf for division with -0 and error or nan with division by the absolute (unsigned) 0. As far as I understand there is no unsigned 0 in IEEE 754, 0 is +0, so in reality it is always signed.

[kstrauser]

Furthermore, it's almost never the case that you legitimately expect to divide by zero. In the case of Python where exception handling is pervasive and idiomatic, it's far more reasonable to treat that as, well, an exception. If you're doing an operation that sometimes execute divide-by-zero, you can watch out for it and handle it appropriately. When you're not expecting to be doing that calculation, it's an error.