How many items in a dictionary share the same value in Python

Question

Is there a way to see how many items in a dictionary share the same value in Python?

Let\'s say that I have a dictionary like:

{\"a\": 600, \"b\": 75         


        

Answer 1

You could use itertools.groupby for this.

import itertools
x = {"a": 600, "b": 75, "c": 75, "d": 90}
[(k, len(list(v))) for k, v in itertools.groupby(sorted(x.values()))]

Answer 2

>>> a = {"a": 600, "b": 75, "c": 75, "d": 90}
>>> d={}
>>> for v in a.values():
...   if not v in d: d[v]=1
...   else: d[v]+=1
...
>>> d
{600: 1, 90: 1, 75: 2}

Answer 3

When Python 2.7 comes out you can use its collections.Counter class

otherwise see counter receipe

Under Python 2.7a3

from collections import Counter
items = {"a": 600, "b": 75, "c": 75, "d": 90}    
c = Counter( items )

print(  dict( c.items() ) )

output is

{600: 1, 90: 1, 75: 2}

Answer 4

>>> a = {"a": 600, "b": 75, "c": 75, "d": 90}
>>> b = {}
>>> for k,v in a.iteritems():
...     b[v] = b.get(v,0) + 1
...
>>> b
{600: 1, 90: 1, 75: 2}
>>>

Answer 5

Use Counter (2.7+, see below at link for implementations for older versions) along with dict.values().