How to sort a list of lists by a specific index of the inner list?

python sorting
oldspice picture oldspice · Nov 13, 2010 · Viewed 282.2k times · Source

I have a list of lists. For example,

[
[0,1,'f'],
[4,2,'t'],
[9,4,'afsd']
]

If I wanted to sort the outer list by the string field of the inner lists, how would you do that in python?

Answer

John La Rooy picture John La Rooy · Nov 13, 2010

This is a job for itemgetter

>>> from operator import itemgetter
>>> L=[[0, 1, 'f'], [4, 2, 't'], [9, 4, 'afsd']]
>>> sorted(L, key=itemgetter(2))
[[9, 4, 'afsd'], [0, 1, 'f'], [4, 2, 't']]

It is also possible to use a lambda function here, however the lambda function is slower in this simple case

Related questions

How do I sort a dictionary by value?

I have a dictionary of values read from two fields in a database: a string field and a numeric field. The string field is unique, so that is the key of the dictionary. I can sort on the keys, but …

Read More
How can I sort a dictionary by key?

What would be a nice way to go from {2:3, 1:89, 4:5, 3:0} to {1:89, 2:3, 3:0, 4:5}? I checked some posts but they all use the "sorted" operator that returns tuples.

Read More
How do I sort a list of dictionaries by a value of the dictionary?

I have a list of dictionaries and want each item to be sorted by a specific value. Take into consideration the list: [{'name':'Homer', 'age':39}, {'name':'Bart', 'age':10}] When sorted by name, it should become: [{'name':'Bart', 'age':10}, {'name':'Homer', …

Read More