[OFF] sed equivalent of something easy in python

[Tim Chase]

On 10/27/10 09:39, Jussi Piitulainen wrote:
>> So, is there some simple expression in Python for this? Just asking
>> out of curiosity when nothing comes to mind, not implying that there
>> should be or that Python should be changed in any way.
>
> To expand, below is the best I can think of in Python 3 and I'm
> curious if there is something much more concise built in that I am
> missing.
>
> def sed(source, skip, keep, drop):
>
>      '''First skip some elements from source,
>      then keep yielding some and dropping
>      some: sed(source, 1, 2, 3) to skip 1,
>      yield 2, drop 3, yield 2, drop 3, ...'''
>
>      for _ in range(0, skip):
>          next(source)
>      while True:
>          for _ in range(0, keep):
>              yield next(source)
>          for _ in range(0, drop):
>              next(source)

Could be done as:  (py2.x in this case, adjust accordingly for 3.x)

   def sed(source, skip, keep, drop):
     for _ in range(skip): source.next()
     tot = keep + drop
     for i, item in enumerate(source):
       if i % tot < keep:
         yield item

-tkc