一. namedtuple命名元组
from collections import namedtuple Student=namedtuple('student','name age') Tom=Student('tom',20) Jerry=Student('jerry',18) print(1,Tom.name) print(2,Jerry.name) print(3,type(Jerry))运行结果:
1 tom 2 jerry 3 <class '__main__.student'> from collections import namedtuple Point=namedtuple('p','x,y') print(0,type(Point)) p1=Point(4,5) print(1,p1) print(2,p1.x) print(3,p1.y) print(4,p1.x+p1.y)运行结果:
0 <class 'type'> 1 p(x=4, y=5) 2 4 3 5 4 9二. defaultdict默认字典 传统:
d1 = {} for k in "abcde": for v in range(5): if k not in d1.keys(): d1[k] = [] d1[k].append(v) print(d1) print(type(d1))运行结果:
{'d': [0, 1, 2, 3, 4], 'c': [0, 1, 2, 3, 4], 'a': [0, 1, 2, 3, 4], 'b': [0, 1, 2, 3, 4], 'e': [0, 1, 2, 3, 4]} <class 'dict'>演化:
from collections import defaultdict d2 = defaultdict(list) for k in "mnopq": for v in range(3): d2[k].append(v) print(d2) print(type(d2))运行结果:
defaultdict(<class 'list'>, {'o': [0, 1, 2], 'p': [0, 1, 2], 'm': [0, 1, 2], 'n': [0, 1, 2], 'q': [0, 1, 2]}) <class 'collections.defaultdict'>三. OrderedDict有序字典
from collections import OrderedDict import random d = {'banana':3,'apple':4,'pear':1,'orange':2} print(1,d) keys = list(d.keys()) random.shuffle(keys) print(2,keys) od = OrderedDict() for key in keys: od[key] = d[key] print(3,od)运行结果:
1 {'orange': 2, 'banana': 3, 'pear': 1, 'apple': 4} 2 ['orange', 'pear', 'banana', 'apple'] 3 OrderedDict([('orange', 2), ('pear', 1), ('banana', 3), ('apple', 4)])