How to generate unique 64 bits integers from Python?

64 bits unique

What's wrong with counting? A simple counter will create unique values. This is the simplest and it's easy to be sure you won't repeat a value.

Or, if counting isn't good enough, try this.

>>> import random
>>> random.getrandbits(64)
5316191164430650570L

Depending on how you seed and use your random number generator, that should be unique.

You can -- of course -- do this incorrectly and get a repeating sequence of random numbers. Great care must be taken with how you handle seeds for a program that starts and stops.

just mask the 128bit int

>>> import uuid
>>> uuid.uuid4().int & (1<<64)-1
9518405196747027403L
>>> uuid.uuid4().int & (1<<64)-1
12558137269921983654L

These are more or less random, so you have a tiny chance of a collision

Perhaps the first 64 bits of uuid1 is safer to use

>>> uuid.uuid1().int>>64
9392468011745350111L
>>> uuid.uuid1().int>>64
9407757923520418271L
>>> uuid.uuid1().int>>64
9418928317413528031L

These are largely based on the clock, so much less random but the uniqueness is better