count values in a dictionary python code example

Example 1: check if key in dictionary python count +1 add if it is

from collections import defaultdict
dct = defaultdict(int)

for key in data:
  dct[key] += 1

# defaultdict(<type 'int'>, {'a': 4, 'c': 3, 'b': 2, 'd': 1})

Example 2: python counting dictionary

counts = dict()
for i in items:
  counts[i] = counts.get(i, 0) + 1