Extracting an undefined number of items from a list
vicente.soler at gmail.com
Mon Apr 12 22:16:40 CEST 2010
On 12 abr, 22:11, Patrick Maupin <pmau... at gmail.com> wrote:
> On Apr 12, 3:05 pm, vsoler <vicente.so... at gmail.com> wrote:
> > Hi everyone,
> > say that 'db' is a list of values
> > say 'i' is a list of indexes
> > I'd like to get a list where each item is i-th element of db.
> > For example:
> > db=[10,20,30,40,50,60,70,80,90] #undefined length
> > i=[3,5,7] #undefined length
> > then result=[30,50,70] # resulting list
> > how can I do this?
> With a list comprehension:
> >>> db=[10,20,30,40,50,60,70,80,90]
> >>> i=[3,5,7]
> >>> [db[x-1] for x in i]
> [30, 50, 70]
Thank you Patrick,
Your quick answer only tells me how much I still have to learn.
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