python 字典

Python 字典

　　字典的定义: 字典是一系列键值对,每个键都与一个值相关联,你可以使用键来访问相对于的值,与键关联的值可以是数字,字符串,列表,乃至字典,

事实上可将任何Python对象作为字典的值.

• 存储列表的字典
• 存储字典的列表
• 存储字典的字典

例一
1 teamList = {'duanxf':'1995','xiaoming':'97'}
2 print(teamList['duanxf'])

字典的键与值的添加
1. 先添加键让后将值赋值个键按照打印的顺序应该是向后添加,但是python中不关心排列顺序的问题,值关系键与值对应的关系

例二
1 teamList = {'duanxf':'1995','xiaoming':'97'}
2 print(teamList)
3 teamList['xiaohong'] = 98
4 teamList['xiaohua'] = 99
5 print(teamList)

修改字典的值

例三
1 dictionaries = {"xiaoqian":"19"}
2 dictionaries["xiaoqian"] = 20
3 print(dictionaries['xiaoqian'])

字典键值对删除

# 使用del 语句直接删除了xiaoqian 所在的键值对
1 dictionaries = {"xiaoqian":"19"}
2 dictionaries["xiaoqian"] = 20
3 print(dictionaries['xiaoqian'])
4 del dictionaries["xiaoqian"]
5 print(dictionaries)