模块_collections包_OrderedDict模块

key键有序的字典

from collections import OrderedDict

# 先回忆下字典的创建
dic1 = dict({})  # 空字典 {}
dic2 = {'0': 48, '1': 50, '2': 51}  # 键值对方式 {'0': 48, '1': 50, '2': 51}
print(dic2.items())  # dict_items([('0', 48), ('1', 50), ('2', 51)])

dic3 = dict([('A', 65), ('B', 66), ('C', 67)])  # 字典的item是元组
print(dic3)  # {'A': 65, 'C': 67, 'B': 66}


odic1 = OrderedDict([('E', 11), ('G', 22), ('F', 33)])
print(odic1)  # OrderedDict([('E', 11), ('G', 22), ('F', 33)])
odic2 = OrderedDict()  # 创建空的有序字典
print(odic2)  # OrderedDict()
# 为字典增添元素
odic2['a'] = 'alt'
odic2['q'] = 'quit'
odic2['c'] = 'ctrl'
# 插入元素的先后顺序决定了字典中key的顺序
print(odic2)  # OrderedDict([('a', 'alt'), ('q', 'quit'), ('c', 'ctrl')])