import counter python

1>>> # Tally occurrences of words in a list
2>>> cnt = Counter()
3>>> for word in ['red', 'blue', 'red', 'green', 'blue', 'blue']:
4...     cnt[word] += 1
5>>> cnt
6Counter({'blue': 3, 'red': 2, 'green': 1})
7
8>>> # Find the ten most common words in Hamlet
9>>> import re
10>>> words = re.findall(r'\w+', open('hamlet.txt').read().lower())
11>>> Counter(words).most_common(10)
12[('the', 1143), ('and', 966), ('to', 762), ('of', 669), ('i', 631),
13 ('you', 554),  ('a', 546), ('my', 514), ('hamlet', 471), ('in', 451)]
14

1Counter({'o': 3, ' ': 3, 'u': 3, 'e': 2, 'l': 2, 't': 2, 'r': 2, '9': 2, 'W': 1,
2 'c': 1, 'm': 1, 'G': 1, 'T': 1, 'i': 1, 'a': 1, 's': 1, '!': 1})
3

1Counter({'x': 4, 'y': 2, 'z': 2})
2

1sum(c.values())                 # total of all counts
2c.clear()                       # reset all counts
3list(c)                         # list unique elements
4set(c)                          # convert to a set
5dict(c)                         # convert to a regular dictionary
6c.items()                       # convert to a list of (elem, cnt) pairs
7Counter(dict(list_of_pairs))    # convert from a list of (elem, cnt) pairs
8c.most_common()[:-n-1:-1]       # n least common elements
9c += Counter()                  # remove zero and negative counts
10