sorting dictionaries by value

[Thomas Guettler]

On Wed, 29 Jan 2003 09:39:52 +0100, Hilbert wrote:

> Hello,
> 
> I have the following dictionary:
> 
>>>> dict = {
> ... "one" : { "red" : 23, "blue" : 99 }, ... "two" : { "red" : 43,
> "blue" : 17 }, ... "three" : { "red" : 34, "blue" : 65 }, ... "four" : {
> "red" : 36, "blue" : 38 } }
> 
> I'd like to print the value of  "blue" sorted and the corresponding key
> of dict, like:
> 
> 17 "two"
> 38 "four"
> 65 "three"
> 99 "one"

Hi Hilbert, 

I would do it like this:

d={"one" : { "red" : 23, "blue" : 99 },
   "two" : { "red" : 43, "blue" : 17 },
   "three" : { "red" : 34, "blue" : 65 },
   "four" : { "red" : 36, "blue" : 38 }
   }

blue_list=[]
for key, value in d.items():
    blue_list.append([value["blue"], key])

def blue_cmp(a, b):
    return cmp(a[0], b[0])

blue_list.sort(blue_cmp)
print blue_list

# --> [[17, 'two'], [38, 'four'], [65, 'three'], [99, 'one']]

-- 
Thomas Guettler <guettli at thomas-guettler.de>
http://www.thomas-guettler.de