Counting the keys of a Mapping isn't possible with collections.Counter but we can count the values:
from collections import Counter
adict = {'a': 5, 'b': 3, 'c': 5, 'd': 2, 'e':2, 'q': 5}
Counter(adict.values())
# Out: Counter({2: 2, 3: 1, 5: 3})
The most common elements are avaiable by the m...