[Numpy-discussion] List/location of consecutive integers

[Andrea Gavana]

Hi All,

    this should be a very easy question but I am trying to make a
script run as fast as possible, so please bear with me if the solution
is easy and I just overlooked it.

I have a list of integers, like this one:

indices = [1,2,3,4,5,6,7,8,9,255,256,257,258,10001,10002,10003,10004]

>From this list, I would like to find out which values are consecutive
and store them in another list of tuples (begin_consecutive,
end_consecutive) or a simple list: as an example, the previous list
will become:

new_list = [(1, 9), (255, 258), (10001, 10004)]

I can do it with for loops, but I am trying to speed up a fotran-based
routine which I wrap with f2py (ideally I would like to do this step
in Fortran too, so if you have a suggestion on how to do it also in
Fortran it would be more than welcome). Do you have any suggestions?

Thank you for your time.

Andrea.

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