On Thu, Jul 12, 2018, 9:31 AM Serhiy Storchaka

12.07.18 15:15, David Mertz пише:

On Thu, Jul 12, 2018, 7:56 AM Serhiy Storchaka I didn't mean any concrete implementation. Sure there are enough efficient and simple. I sometimes need a sequence of prime numbers for solving toy problems, and quickly write something like:

def primes(n): return (i for i in range(2, n) if all(i % j for j in primes(int(sqrt(i)) + 1)))

Having such feature in the stdlib would be very convenient. Any reasonable implementation is enough efficient for my purposes.

That's the point I was getting at. "For your purposes" isn't general enough to include in the standard library. There are quite a few algorithms and efficiency trade-offs to decide on. It's not clear to me that any choice is sufficiently "one size fits all" to include. I'm not saying there definitely IS NOT a reasonable compromise approach to these things, but I'd have to judge concrete suggestions... Or better still, people with better knowledge of number theory than mine should make those judgements.