why generator assigned to slice?

[Peter Otten]

ana sanchez wrote:

> i found this when i read the source of a program in python:
> 
>         self.__chunks[start:end] = (chunk for i in xrange(start, end))

> what utility has to assign a generator to a slice???  ?the *final
> result* isn't the same as this?:
> 
>         self.__chunks[start:end] = [chunk for i in xrange(start, end)]

Whoever used the first variant probably was hoping that it was either faster 
or used less peak memory. I think the latter is wrong, and the former can 
easily be checked:

$ python -m timeit -s'chunk = "yadda"; chunks = range(100); start = 20; end 
= 50' 'chunks[start:end] = (chunk for i in xrange(start, end))'
100000 loops, best of 3: 9.02 usec per loop

$ python -m timeit -s'chunk = "yadda"; chunks = range(100); start = 20; end 
= 50' 'chunks[start:end] = [chunk for i in xrange(start, end)]'
100000 loops, best of 3: 4.16 usec per loop

$ python -m timeit -s'chunk = "yadda"; chunks = range(100); start = 20; end 
= 50' 'chunks[start:end] = [chunk]*(end-start)'
1000000 loops, best of 3: 1.02 usec per loop