Python sort dictionary keys by letters and then numbers

Question

Say I have a dictionary like this,

d = {"John1" : "blah blah", "John2" : "blah blah", "John11" : "blah blah", "Dave1" : "blah blah", "Dave2" : "blah blah", "Dave13" : "blah blah", "Dave23" : "blah blah"}

If want to be able to sort this so it is

d = {"Dave1" : "blah blah", "Dave2" : "blah blah", "Dave13" : "blah blah", "Dave23" : "blah blah", "John1" : "blah blah", "John2" : "blah blah", "John11" : "blah blah", }

Is there a way I can sort the keys of this dictionary alphabetically, then numerically?

It is not possible to sort a dict, only to get a representation of a dict that is sorted. — Alok, Jun 10 '14 at 03:54

MrAlias · Answer 1 · 2014-06-11T08:57:34.980

1

Keep in mind that sorting the dictionary itself is really not what the data structure is intended for, but if you are looking for just a sorted list of the dictionary keys:

sorted(d.keys())

Where you can provide sorted with all sorts of good sorting functions to satisfy what ever burning desire you have. :)

Given how the keys are named a sorting function might look like...

def my_key(item):
    alpha = ''.join(i for i in item if i.isalpha())
    num = ''.join(i for i in item if i.isdigit())
    if num:
        return (alpha, int(num))
    return (alpha, 0)

and then:

sorted(d.keys(), key=my_key)

edited Jun 11 '14 at 08:57

answered Jun 10 '14 at 04:02

MrAlias

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This does not sort by letters and then numbers. ['Dave1', 'Dave13', 'Dave2', 'Dave23', – user2909250 Jun 10 '14 at 04:55
@user2909250 as mentioned in his answer, you have to provide `sorted` with the sorting function you want. The vanilla `sorted` function won't sort the way you want it to – Dan Oberlam Jun 10 '14 at 05:13
Then what is the sorted function that I need? – user2909250 Jun 11 '14 at 01:05
How can I keep the dictionary keys intact with the values? – user2909250 Jun 12 '14 at 03:54

Python sort dictionary keys by letters and then numbers

1 Answers1