#Author:ersa

 '''

 key-value 键值对

 字典是无序的，不需要下标，有key

 字典的查找、修改、添加、判断、删除

 '''

 info = {

     'stu1101': "TengLan Wu",

     'stu1102': "LongZe Luola",

     'stu1103': "XiaoZe Maliya",

 }

 #输出

 print("输出所有的key".center(50,'='))

 print(info.keys())

 print("=".center(70,'='))

 print("输出所有的 值".center(50,'='))

 print(info.values())

 print("=".center(70,'='))

 #循环输出键-值

 print("输出键-值".center(50,'='))

 for i in info:

     print(i,info[i])

 print("=".center(70,'='))

 #设置默认值：如果有key-value 则返回，没有则创建

 print("取key-value值，没有则创建".center(50,'='))

 info.setdefault("stu1106","Alex")

 print(info)

 print("=".center(70,'='))

 #查找

 print(info)

 print("查找".center(50,'='))

 print(info["stu1101"])

 #安全查找--->查找的值不存在时不会报错

 print("安全查找".center(50,'='))

 print(info.get('stu1104'))

 #判断

 print("判断key是否存在".center(50,'='))

 print('stu1104' in info)

 #修改

 print("修改".center(50,'='))

 print(info)

 info["stu1101"] = "武藤兰"

 #添加

 print("添加".center(50,'='))

 info["stu1104"] = "苍老师"

 print(info["stu1104"])

 #删除 Python--->通用删除del

 print("删除".center(50,'='))

 #del info["stu1101"]

 print(info)

 #字典删除

 print("字典删除".center(50,'='))

 #info.pop("stu1101")

 print(info)

 #随机删除

 print("随机删除".center(50,'='))

 #info.popitem()

 print(info)

 #字典转列表

 print("字典转列表".center(50,'='))

 print(info.items())

 print("=".center(70,'='))

 #update 更新字典

 b = {

     'stu1101':"alex",

     1:3,

     2:5

 }

 info.update(b)

 print("合并字典，有重合key，则更新".center(50,'='))

 print(info)

 print("=".center(70,'='))

 #初始化新的字典

 print("初始化新的字典".center(50,'='))

 c = dict.fromkeys([6,7,8],'test')

 print(c)

 print("=".center(70,'='))