Building a list of dictionary values, sorted by key

Question

I have a python dictionary that looks something like this:

attributes = {     'size': ['s','m','l'],     'color': ['black', 'orange'], } 

I want to get a list of values. If I use values(), I get this:

>>> attributes.values() [['black', 'orange'], ['s', 'm', 'l']] 

However, I want the resulting list of lists to be sorted by the dictionary key in reverse order -- ie, size and then color, not color and then size. I want this:

[['s', 'm', 'l'], ['black', 'orange']] 

I do not necesarilly know what the dictionary keys will be beforehand, but I do always know if I want them in alphabetical or reverse alphabetical order.

Is there some pythonic way to do this?

The only thing I can think of seems... not very python-like:

keys = sorted(attributes.keys(), reverse=True) result = [] for key in keys:     result.append(attributes[key]) 

It's hard to go from attributes.values() to all of that just to sort the list!

Answer 1

This code:

keys = sorted(attributes.keys(), reverse=True) result = [] for key in keys:     result.append(attributes[key]) 

Is basically the use case for which list comprehensions were invented:

result = [attributes[key] for key in sorted(attributes.keys(), reverse=True)] 

Answer 2

The easiest way is to use OrderedDict, which remembers the order in which the elements have been inserted:

import collections  result = collections.OrderedDict(sorted(attributes.items(), reverse=True))  >>> result.values() [['s', 'm', 'l'], ['black', 'orange']]