Bit of a python newbie, but I got the following list of tuples. I need to sort it by value and if the value is the same, solve ties alphabetically. Here\'s a sample:
In this instance, I'd use a lambda function as the key
argument to sort()
/sorted()
:
In [59]: sorted(list_of_medals, key=lambda x:(-x[1],x[0]))
Out[59]:
[('Sweden', 24),
('Germany', 16),
('Ireland', 10),
('Russia', 10),
('Spain', 9),
('Albania', 8),
('Lithuania', 7),
('Iceland', 6),
('Italy', 5),
('Malta', 5),
('Estonia', 4),
('Serbia', 4),
('Turkey', 4),
('Azerbaijan', 2),
('Moldova', 2)]
The negation of x[1]
is needed to sort the medals in descending order while sorting country names in ascending order (simply setting reverse=True
wouldn't achieve that).
As several people have pointed out in the comments, a more general way to do a complex sort on a compound key is to perform several sorting steps. To do this, sort on one component at a time, starting with the least significant one:
In [67]: temp = sorted(list_of_medals, key=itemgetter(0))
In [68]: sorted(temp, key=itemgetter(1), reverse=True)
Out[68]:
[('Sweden', 24),
('Germany', 16),
('Ireland', 10),
('Russia', 10),
...
This relies on the fact that Python's sort is stable, meaning that items that compare equal are never reordered.