[EMAIL PROTECTED] writes:
> Does anybody know a faster way to do this? (finding the difference all
> items in list a that are not in list b)?
>>> a = [3, 7, 16, 1, 2, 19, 13, 4, 0, 8] # random.sample(range(20),10)
>>> b = [15, 11, 7, 2, 0, 3, 9, 1, 12, 16] # similar
>>> sorted(set(a)-set(b))
>>> [4, 8, 13, 19]
but you probably don't want to use that kind of implementation.
Here's a version using generators:
def sieve_all(n = 100):
# yield all primes up to n
stream = iter(xrange(2, n))
while True:
p = stream.next()
yield p
def s1(p, stream):
# yield all non-multiple of p
return (q for q in stream if q%p != 0)
stream = s1(p, stream)
# print all primes up to 100
print list(sieve_all(100))
It's cute, but horrendous once you realize what it's doing ;-)
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