Sorting a list

[Peter Otten]

Random832 wrote:

> On Mon, Apr 4, 2016, at 02:56, Peter Otten wrote:
>> > That works well.  Why is it 'cheating'?
>> 
>> On second thought it isn't ;)
> 
> It does require a numeric type, though. There are lots of types that are
> orderable but do not have a negation operator that provides a key with
> reversed ordering.

If you are willing to accept the overhead you can use a wrapper class:

>>> import functools
>>> @functools.total_ordering
... class neg:
...     def __init__(self, key):
...         self.key = key
...     def __lt__(self, other):
...         return other.key < self.key
... 
>>> sorted("abcde", key=neg)
['e', 'd', 'c', 'b', 'a']