Python按元组中的值的长度对List进行排序

Question

I am having difficulty sorting a list of tuples. I would like to sort by the length of a string in the list.

For example:

l = [(99,'bbc', 121),(33,'abcd', 231),(44,'zb', 148), (23,'abcde',221)]

if I sort by element 1:

l.sort(key=itemgetter(1), reverse=True)

This will sort on the alphabetical ranking of the strings, not the length. I would prefer to sort in-place and reverse sort, with longest string first.

I can use a lambda and cmp,

l.sort(lambda x,y: cmp(len(x[1]), len(y[1])), reverse=True)

but is there a more elegant, or pythonic way using key and/or itemgetter?

Answer 1

Well you can make the lambda simpler:

l.sort(key=lambda t: len(t[1]), reverse=True)

Also, don't use list as a variable name; it's already taken by a built-in function.