[Python-ideas] Pass a function as the argument "step" of range()

[Ron Adam]

On 07/02/2015 02:30 AM, Pierre Quentel wrote:
>
> Iterating on the powers of 2 below N would be done by :
>
> for i in Range(1, N, lambda x:x*2)
>
> I haven't seen this discussed before, but I may not have searched enough.
>
> Any opinions ?

I'm surprised no one mentioned this!?

 >>> for i in map(lambda x:2**x, range(1, 10)):
...     print(i)
...
2
4
8
16
32
64
128
256
512

It looks like map returns a map object which is a generator.  You just need 
to use the power of 2 formula rather than accumulate it.  That's actually 
more flexible solution as your range can start some place other than 1.

 >>> for i in map(lambda x:2**x, range(5, 10)):
...     print(i)
...
32
64
128
256
512


Cheers,
    Ron