How to sort a Python dict (dictionary) by keys or values

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http://www.saltycrane.com/blog/2007/09/how-to-sort-python-dictionary-by-keys/

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How to sort a dict by keys (Python 2.4 or greater):

mydict = {'carl':40,
          'alan':2,
          'bob':1,
          'danny':3}

for key in sorted(mydict.iterkeys()):
    print "%s: %s" % (key, mydict[key])

Results:

alan: 2
bob: 1
carl: 40
danny: 3

Taken from the Python FAQ: http://www.python.org/doc/faq/general/#why-doesn-t-list-sort-return-the-sorted-list

To sort the keys in reverse, add reverse=True as a keyword argument to the sorted function.

How to sort a dict by keys (Python older than 2.4):

keylist = mydict.keys()
keylist.sort()
for key in keylist:
    print "%s: %s" % (key, mydict[key])

How to sort a dict by value (Python 2.4 or greater):

for key, value in sorted(mydict.iteritems(), key=lambda (k,v): (v,k)):
    print "%s: %s" % (key, value)

Results:

bob: 1
alan: 2
danny: 3
carl: 40

Taken from Nick Galbreath's Digital Sanitation Engineering blog article


See also:

• The documentation for sorted in 2.1 Built-in Functions and the .sort() method in 3.6.4 Mutable Sequence Types in the Python Library Reference.