[Baypiggies] manipulating lists question

[Monte Davidoff]

On 12/5/13 12:06 AM, Vikram K wrote:
> Any suggestions on what i have to do to go from x to y?
>
> >>> x
> [['cat', 'NM123', 12], ['cat', 'NM234', 12], ['dog', 'NM56', 65]]
> >>> y = [['cat','NM123, NM234', 12], ['dog', 'NM56', 65]]

How about this:

     from itertools import groupby
     from operator import itemgetter
     key = itemgetter(0, 2)
     y = [[k[0], ', '.join(h[1] for h in g), k[1]]
for k, g in groupby(sorted(x, key=key), key)]

Monte
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