Creating slice notation from string

[Jan Kaliszewski]

03-09-2009 o 00:55:10 Bob van der Poel <bob at mellowood.ca> wrote:

>> For a one-liner:
>>
>>    x[slice(*map(int, x[1:-1].split(':')))]
>
> Thanks.
>
> Almost works :)
>
> For s="[2]" and s="[1:2]" it's fine. But, if I have
>
> s = "[:2]" then I get:
>
>>>> x[slice(*[int(i) for i in s.strip("[]").split(":")])]
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> ValueError: invalid literal for int() with base 10: ''
>
> Similar problem with  [2:].
>
> Ideas?

     x = [1,4,3,5,4,6,5,7]
     s = '[3:6]'

     x[slice(*((int(i) if i else None)
               for i in s.strip("[]").split(":")))]

Cheers,
*j

-- 
Jan Kaliszewski (zuo) <zuo at chopin.edu.pl>