Example 1: collections.counter in python
>>> from collections import Counter
>>>
>>> myList = [1,1,2,3,4,5,3,2,3,4,2,1,2,3]
>>> print Counter(myList)
Counter({2: 4, 3: 4, 1: 3, 4: 2, 5: 1})
>>>
>>> print Counter(myList).items()
[(1, 3), (2, 4), (3, 4), (4, 2), (5, 1)]
>>>
>>> print Counter(myList).keys()
[1, 2, 3, 4, 5]
>>>
>>> print Counter(myList).values()
[3, 4, 4, 2, 1]
Example 2: counter most_common
most_common([n])¶
Return a list of the n most common elements and their counts from the most common to the least. If n is omitted or None, most_common() returns all elements in the counter.
Elements with equal counts are ordered arbitrarily:
>>> Counter('abracadabra').most_common(3)
[('a', 5), ('r', 2), ('b', 2)]
Example 3: python counting dictionary
counts = dict()
for i in items:
counts[i] = counts.get(i, 0) + 1