On Fri, 07 Sep 2007 08:42:45 -0700, Paul Rubin wrote:
> Steven D'Aprano <[EMAIL PROTECTED]> writes:
>> def unique_id():
>> n = 1234567890
>> while True:
>> yield n
>> n += 1
>
> unique_id = itertools.count(1234567890)
Sweet!
I really must make itertools second-nature. I always forget it.
>> which is easy enough, but I thought I'd check if there was an existing
>> solution in the standard library that I missed. Also, for other
>> applications, I might want them to be rather less predictable.
>
> def unique_id():
> return os.urandom(10).encode('hex')
Any time I see something using a random number to generate IDs, I worry
about collisions. Am I being paranoid? (But even paranoids write code
with bugs...)
Here's something which is a little less predictable than a straight
counter:
def unpredictable_counter(n=12345678):
while True:
n += random.randint(1, 68)
yield n
def more_unpredictable_counter(n=1234567):
uc = unpredictable_counter(n)
pool = []
while True:
if not pool:
pool = [None]*99
for i in range(99):
pool[i] = uc.next()
random.shuffle(pool)
yield pool.pop()
--
Steven.
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