remove a list from a list
Rares Vernica
rvernica at gmail.com
Fri Nov 17 14:04:25 EST 2006
That is a nice solution.
But, how about modifying the list in place?
That is, l would become ['c', 'D'].
Thanks a lot,
Ray
Tim Chase wrote:
>> I have a list like
>> e = ['a', 'b', 'e']
>> and another list like
>> l = ['A', 'a', 'c', 'D', 'E']
>> I would like to remove from l all the elements that appear in e
>> case-insensitive. That is, the result would be
>> r = ['c', 'D']
>>
>> What is a *nice* way of doing it?
>
>
> Well, it's usually advantageous (for speed purposes) to make a
> set out of your lookup data. One can then use it for a list
> comprehension something like
>
> >>> e = ['a', 'b', 'e']
> >>> l = ['A', 'a', 'c', 'D', 'E']
> >>> s = set(e)
> >>> [x for x in l if x.lower() not in s]
> ['c', 'D']
>
> This presumes that "e" is all lowercase letters. Otherwise, you
> can force it with
>
> s = set(c.lower() for c in e)
>
> -tkc
>
>
>
>
>
>
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