DAY5：字典

无序性：

  # -*- coding:utf-8 -*-
  # Author: TanJincheng

  room = {
      "s2": "han meimei",
      "s1": "li lei",
      "s3": "zhao rui",
      "s4": "er gou",
      "s5": "liang cheng"
  }
  print(room)#字典是无序的

  >{'s2': 'han meimei', 's1': 'li lei', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}

替换：

 room["s1"] = "wang gang"#改变字典内容s1

 >{'s2': 'han meimei', 's1': 'wang gang', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}

添加：

 room["s6"] = "zheng liang"#搜索字典值s6，存在就改，不存在就增添
 print(room)
 room["s1"]="hong li"
 print(room)

 >{'s2': 'han meimei', 's1': 'li lei', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng', 's6': 'zheng liang'}
 >{'s2': 'han meimei', 's1': 'hong li', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}

删除：

 del room["s1"]#删除s1
 print(room)
 room.pop("s2")#删除s2
 print(room)
 room.popitem()#随机删除
 print(room)

 >{'s2': 'han meimei', 's3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}
 >{'s3': 'zhao rui', 's4': 'er gou', 's5': 'liang cheng'}
 >{'s3': 'zhao rui', 's4': 'er gou'}

判断：

 >>>"s5" in room#控制台判断
 True

 >>>room.get("s2")#控制台查找
 'han meimei'

 >>>room["s1"]#控制台查找
 'li lei'

 >>>room["s7"]#控制台查不到报错
 Traceback (most recent call last):
   File "<input>", line 1, in <module>
 KeyError: 's7'
 >>>room.get("s7")#无内容
 None

输出key值：

 for i in room:#输出key值

     print(i)

 >s2
 >s1
 >s3
 >s4
 >s5

其他：

 #values
 >>>room.values()
 dict_values(['han meimei', 'li lei', 'zhao rui', 'er gou', 'liang cheng'])

 #key
 >>>room.keys()
 dict_keys(['s2', 's1', 's3', 's4', 's5'])