Question

I have one question about writing a code on dictionaries i have done the coding but i am confused on one part this is what it says the parameter name is sort_by_value: “(dict of {immutable_type:int}) -> list” and the description is “Return a list of keys in the dictionary sorted in ascending order according to their values. Keys with identical values might be sorted in any order. “

and my code that i wrote is

    def sort_by_value(dict):
        """
        (dict of {immutable_type:int}) -> list   """
        L = []
        for x in dict.values():
            L.append(x)
        L.sort()
        print L

this code ascends it with the value only like say if I had a dictionary

    nd = {} 
    nd['john'] = 109090 
    nd['albert'] = 1900 
    nd['Tim'] = 18000 
    sort_by_value(nd)

I get the list [1900, 18000, 109090] but I need to get the keys associated with those values like I want [‘albert’, ‘Tim’, ‘john’]

I did try giving it a try and tried to introduce another for loop
right before Print L I wanted to write

   keyList= []

    for x in L:
        keyList.append(dict.get())
        if 

but i dont know if that would work please need of helppp

Answer 1

You can use built-in sorted function to sort tuple of that dictionary.

nd = {}
nd['john'] = 109090
nd['albert'] = 1900
nd['Tim'] = 18000

print sorted(nd.items(), key=lambda x: x[1])

Which will return:

[('albert', 1900), ('Tim', 18000), ('john', 109090)]

if you want to get keys only:

print map(lambda x: x[0], sorted(nd.items(), key=lambda x: x[1]))

will give you:

['albert', 'Tim', 'john']

Refer: http://wiki.python.org/moin/HowTo/Sorting/