Chance of negative ID

[nixie]

Hi,
I'm curious about the subtraction of 1 when generating new ID. Why is it here? The output of random.Random().getrandbits(k) is already in range [0,2^(k-1)], so subtracting 1 can result in new ID equal to -1 (even though with probability 1/2^64).

basictracer-python/basictracer/util.py

Line 21 in 066cc17

return guid_rng.getrandbits(64) - 1