[Tutor] manipulating list of lists

John Fouhy john at fouhy.net
Tue Oct 25 05:12:48 CEST 2005


On 25/10/05, Brian van den Broek <broek at cc.umanitoba.ca> wrote:
> To sort by the second item, try
>
>  >>> def sort_by_second(sequence):
>         decorated = [(x[1], x) for x in sequence]
>         decorated.sort()
>         return [x[1] for x in decorated]

With python2.4, you can use the key= argument to sort.

eg:
>>> arr = [('a', 5), ('b', 3), ('c', 7), ('d', 1), ('e', 2)]
>>> arr.sort(key=lambda x: x[1])
>>> arr
[('d', 1), ('e', 2), ('b', 3), ('a', 5), ('c', 7)]

--
John.


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