adii1823
19 lines
444 B
Python
19 lines
444 B
Python
# defaultdict.py
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>>> d = {}
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>>> d['age'] = d.get('age', 0) + 1 # age not there, we get 0 + 1
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>>> d
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{'age': 1}
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>>> d = {'age': 39}
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>>> d['age'] = d.get('age', 0) + 1 # age is there, we get 40
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>>> d
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{'age': 40}
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>>> from collections import defaultdict
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>>> dd = defaultdict(int) # int is the default type (0 the value)
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>>> dd['age'] += 1 # short for dd['age'] = dd['age'] + 1
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>>> dd
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defaultdict(<class 'int'>, {'age': 1}) # 1, as expected
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