why python don't support "extended slice direct assignment" for lists?

[Shashwat Anand]

On Sat, Jul 3, 2010 at 4:54 AM, Robert William Hanks <
astroultraman at gmail.com> wrote:

> why pure python don't support "extended slice direct assignment" for lists?
>
> today we have to write like this,
>
> >>> aList=[0,1,2,3,4,5,6,7,8,9]
> >>> aList
> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
> >>> aList[::2]= [None]*len(aList[::2])  #or do the math by hand, what's not
> always possible
>

Can you show me a case where it really is cumbersome.


> >>> aList
> [None, 1, None, 3, None, 5, None, 7, None, 9]
>
> why not accept syntax like this for extended slice
>
> aList[::2] = None
>
> when let's say, the left side is a list and the right side is bool, int or
> float.
> the laborious [nunber]*len(aList[::2]) seens to me less readable when you
> want to set lost of items of a list to the same number.
> Also correct me if i am wrong, calling len() and building a list to this
> kind of operation seems a waste.
>

>>> aList[::2]
[0, 2, 4, 6, 8]
Which means you are doing [0, 2, 4, 6, 8] = None, which is plain and simple
- wrong. How will you define the legitimacy of this statement.
What you are basically doing here is,,

>>> [None]*len(aList[::2])
[None, None, None, None, None]
>>> aList[::2]
[0, 2, 4, 6, 8]

Setting [0, 2, 4, 6, 8] to [None, None, None, None, None], thereby operating
on two similar data structure (here list)


> Just want some feedback.
>

Just my thoughts.

~l0nwlf
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