标签:根据 span color class ems def 基础 style pytho
字典中每个值都有一个唯一的key,key需要被哈希,可以是可以是数字、字符串、元组;用大括号‘{}‘将内容扩起来,且是无序的。
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 print(info) 3 结果: 4 {‘age‘: 16, ‘work‘: ‘it‘, ‘name‘: ‘fox‘}
通过需要增加的key和值,直接赋值给字典,即可添加元素。
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 info[‘sex‘] = ‘M‘ 3 print(info) 4 结果: 5 {‘name‘: ‘fox‘, ‘age‘: 16, ‘work‘: ‘it‘, ‘sex‘: ‘M‘}
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 info.pop(‘work‘) 3 print(info) 4 结果: 5 {‘name‘: ‘fox‘, ‘age‘: 16}
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 info.clear() 3 print(info) 4 结果: 5 {}
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 info[‘work‘] = ‘ui‘ 3 print(info) 4 结果: 5 {‘work‘: ‘ui‘, ‘age‘: 16, ‘name‘: ‘fox‘}
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 info1 = {‘age‘:18,‘sex‘:‘M‘} 3 info.update(info1) 4 print(info) 5 结果: 6 {‘work‘: ‘it‘, ‘age‘: 18, ‘name‘: ‘fox‘, ‘sex‘: ‘M‘}
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 print(info.get(‘age‘)) 3 结果: 4 16
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 info.setdefault(‘work‘) 3 print(info.setdefault(‘work‘)) 4 print(info) 5 info.setdefault(‘ff‘) 6 print(info.setdefault(‘ff‘)) 7 print(info) 8 结果: 9 it 10 {‘work‘: ‘it‘, ‘age‘: 16, ‘name‘: ‘fox‘} 11 None 12 {‘work‘: ‘it‘, ‘age‘: 16, ‘name‘: ‘fox‘, ‘ff‘: None}
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 print(info.keys()) 3 结果: 4 dict_keys([‘age‘, ‘work‘, ‘name‘])
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 print(info.values()) 3 结果: 4 dict_values([‘it‘, 16, ‘fox‘])
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 for key,value in info.items(): 3 print(key,‘:‘,value) 4 结果: 5 age : 16 6 name : fox 7 work : it
OrderedDict类可以将字典变得有序,正常情况下字典是无序的,一个普通的字典,如果键值对一样,即使顺序不一样,那么两个字典是相等的。
1 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 2 info1 = {‘age‘:16,‘work‘:‘it‘,‘name‘:‘fox‘} 3 print(info == info1) 4 结果: 5 True
使用OrderedDict()方法后,键值对一样,但是顺序不同时,不相等;OrderedDict()方法是collections模块的方法,不是内置方法,故需要导入,即(from collections import OrderedDict)指导入collections模块的OrderedDict类。
1 from collections import OrderedDict 2 info = {‘name‘:‘fox‘,‘age‘:16,‘work‘:‘it‘} 3 info1 = {‘age‘:16,‘work‘:‘it‘,‘name‘:‘fox‘} 4 info1 = OrderedDict() 5 print(info == info1) 6 结果: 7 False
标签:根据 span color class ems def 基础 style pytho
原文地址:https://www.cnblogs.com/foxshu/p/12033924.html