[Tutor] Geometric sequence

[bob gailer]

On 10/30/2013 1:08 PM, Peter O'Doherty wrote:
> Hi List,
>
> I know a geometric sequence can be produced by:
>
> series = [2**x for x in range(7)]
>
> But I would like to curtail the sequence before the last element 
> excedes a certain value.
import itertools
series = [2**x for x in itertools.takewhile(lambda x: 2**x<60, range(7))]

if the limit is really large you could calculate it once:

import itertools
import math
limit =  int(math.log(60)) + 1
series = [2**x for x in itertools.takewhile(lambda x:x<limit, range(7))]

which in turn leads to:

import math
series = [2**x for x in range(int(math.log(60)) + 2)]

-- 
Bob Gailer
919-636-4239
Chapel Hill NC