Scott David Daniels wrote:
> Dan Sommers wrote:
>> ...
>> longest_list, longest_length = list_of_lists[ 0 ], len(
>> longest_list )
>> for a_list in list_of_lists[ 1 : ]:
>> a_length = len( a_list )
>> if a_length > longest_length:
>> longest_list, longest_length = a_list, a_length
>> will run faster than sorting the list just to pick off one element (O(n)
>> vs. O(n log n) for all of you Big-Oh notation fans out there; you know
>> who you are!).
>
> Or, more succinctly, after:
> list_of_lists = [["q", "e", "d"],
> ["a", "b"],
> ["a", "b", "c", "d"]]
> You can find the longest with:
> maxlength, maxlist = max((len(lst), lst) for lst in list_of_lists)
> or (for those pre-2.5 people):
> maxlength, maxlist = max([(len(lst), lst) for lst in list_of_lists])
Generator expressions worked in 2.4 too. If you're using 2.5, you should
take advantage of the key= argument to max and skip the generator
expression entirely::
>>> list_of_lists = [["q", "e", "d"],
... ["a", "b"],
... ["a", "b", "c", "d"]]
>>> maxlist = max(list_of_lists, key=len)
>>> maxlist, len(maxlist)
(['a', 'b', 'c', 'd'], 4)
STeVe
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