defaultdict documentation code example
Example 1: python defaultdict
>>> from collections import defaultdict
>>> ice_cream = defaultdict(lambda: 'Vanilla')
>>>
>>> ice_cream = defaultdict(lambda: 'Vanilla')
>>> ice_cream['Sarah'] = 'Chunky Monkey'
>>> ice_cream['Abdul'] = 'Butter Pecan'
>>> print ice_cream['Sarah']
Chunky Monkey
>>> print ice_cream['Joe']
Vanilla
>>>
Example 2: .defaultdict
>>> from collections import defaultdict
>>> food_list = 'spam spam spam spam spam spam eggs spam'.split()
>>> food_count = defaultdict(int)
>>> for food in food_list:
... food_count[food] += 1
...
defaultdict(<type 'int'>, {'eggs': 1, 'spam': 7})
>>>