Find Items & Indices In A List...

[Bengt Richter]

On Fri, 10 Dec 2004 16:01:26 +0100, andrea.gavana at agip.it wrote:

>Hello NG,
>
>      I was wondering if there is a faster/nicer method (than a for loop)
>that will allow me to find the elements (AND their indices) in a list that
>verify a certain condition. For example, assuming that I have a list like:
>
>mylist = [0, 1, 1, 1, 1, 5, 6, 7, 8, 1, 10]
>
>I would like to find the indices of the elements in the list that are equal
>to 1 (in this case, the 1,2,3,4,9 elements are equal to 1). I could easily
>use a for loop but I was wondering if there is a faster method...
>
>Thanks for every suggestion.
>
One way:

 >>> mylist = [0, 1, 1, 1, 1, 5, 6, 7, 8, 1, 10]
 >>> [i for i,v in enumerate(mylist) if v==1]
 [1, 2, 3, 4, 9]

Regards,
Bengt Richter