Sorting dictionary keys in python

Question

I have a dict where each key references an int value. What's the best way to sort the keys into a list depending on the values?

Also, this asks about sorting by key, the linked answer is about sorting by value. — ForeverWintr, Jun 12 '13 at 08:31

score 358 · Answer 1 · answered Feb 22 '09 at 21:53

358

I like this one:

sorted(d, key=d.get)

answered Feb 22 '09 at 21:53

dF.

Nice, thought it would be nice to have an elegant solution which gives (key,value) pairs sorted by key. ...and doesn't require providing the dict variable name more than once (I tend to have very long descriptive variable names). d.iteritems() still seems the most useful. – travc Jan 30 '13 at 08:51

score 107 · Accepted Answer · edited Oct 20 '10 at 12:23

107

>>> mydict = {'a':1,'b':3,'c':2}
>>> sorted(mydict, key=lambda key: mydict[key])
['a', 'c', 'b']

edited Oct 20 '10 at 12:23

dbr

answered Feb 22 '09 at 21:21

Markus Jarderot

score 17 · Answer 3 · edited Jun 27 '13 at 13:57

17

my_list = sorted(dict.items(), key=lambda x: x[1])

edited Jun 27 '13 at 13:57

answered Feb 22 '09 at 21:22

Jonas Kölker

1

@user815423426 you edited my post `s/list/my_list/` because "list is a keyword in python". Your edit is fine, but list is not a keyword (c.f. https://docs.python.org/3/reference/lexical_analysis.html#keywords), so my program fragment would (bytecode-)compile and run. It is however a name in the `__builtins__` namespace, and it is bad practice to shadow that name—with a locale variable named list—and horrible to override it—with a global variable named list, e.g. `list = tuple`. – Jonas Kölker Jun 29 '14 at 14:29

score 4 · Answer 4 · answered Feb 22 '09 at 21:24

4

[v[0] for v in sorted(foo.items(), key=lambda(k,v): (v,k))]

answered Feb 22 '09 at 21:24

Can Berk Güder

4 Answers4