Python Defaultdict
2021/12/14 14:17:02
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In Dictionary, the key must be unique and immutable. This means that a Python Tuple can be a key whereas a Python List can not. A Dictionary can be created by placing a sequence of element within curly {} braces, separated by ‘comma’.
Defaultdict is a container like dictionaries present in the module collections. Defaultdict is a sub-call of the dictionary class that returns a dictionary-like object. The functionality of both dictionaries and defaultdict are almost same except for the fact that defaultdict never raises a KeyError. It provides a default value for the key that does not exists.
Syntax: defaultdict(default_factory) Parameters: default_factory: A function returning the default value for the dictio nary defined. If this argument is absent then the dictionary raises a KeyError
from collections import defaultdict d = defaultdict(lambda: "Not Present") d["a"] = 1 d["b"] = 2 print(d["a"]) # 1 print(d["b"]) # 2 print(d["c"]) # Not Present
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