# Silly question

David C Ullrich dullrich at sprynet.com
Fri Aug 21 21:45:55 CEST 2009

```On Fri, 21 Aug 2009 14:40:30 -0500, David C Ullrich wrote:

> On Thu, 20 Aug 2009 16:51:00 -0700, Aahz wrote:
>
>> In article <mailman.143.1250793404.2854.python-list at python.org>,
>> Benjamin Kaplan  <benjamin.kaplan at case.edu> wrote:
>>>On Thu, Aug 20, 2009 at 2:13 PM, David C Ullrich<dullrich at sprynet.com>
>>>wrot= e:
>>>>
>>>> I just noticed that
>>>> sequence[i:j:k]
>>>
>>>Well, I got some good news and some bad news. According to the docs, it
>>>existed in 1.4 but the built-in sequences didn't support it until 2.3.
>>>It's not used that often anyway so you haven't been missing much.
>>
>> Except that it's canonical for one specific operation:
>>
>> 'reverseme'[::-1]
>
> It's like you guys are a bunch of programmers or something:
>
> from math import sqrt
>
> def Primes(n):
>   """Return a list of the primes < n""" sieve = range(n)
>   for k in range(2,int(sqrt(n))+2):
>     sieve[::k] = [1]*((n+k-1)/k)
>   return [p for p in sieve if p > 1]

Oops. Should have tested that a little more carefully
before posting. No time to fix it right now, customer just
got here. Let's just say we're looking for the primes
between sqrt(n) and n...

```