python---数据类型---字典

字典学习

 1 dict = {
 2     'stu1101':"Peter",
 3     'stu1102':"Jack",
 4     'stu1103':"Alex",
 5 }
 6 print(dict)
 7 print(dict.values())            #打印字典里的值
 8 print(dict.keys())              #打印字典里的key
 9 
10 dict.setdefault("stu1105","LC")     #如果key存在,则返回原有的值,如果key不存在,则添加key和相应的值到字典里
11 print(dict)
12 
13 dict2 ={
14     "stu1101":"GL",
15     1:2,
16     3:5,
17 }
18 dict.update(dict2)              #更新字典,如果dict2中的key在dict中存在,则更新dict中key对应的值,如果没有,则添加至dict中
19 print(dict)
20 
21 print(dict.items())         #将字典变成一个列表
22 
23 
24 c = dict.fromkeys(["LC","HL","GL"],["classmate",{"Name":"XLL"},"19"])       #前面为key,后面赋值给key,如果修改Value,则会所有改
25 print(c)
打印结果:
{'LC': ['classmate', {'Name': 'XLL'}, '19'], 'HL': ['classmate', {'Name': 'XLL'}, '19'], 'GL': ['classmate', {'Name': 'XLL'}, '19']}
26 c["LC"][1]["Name"]="Xlingling" 27 print(c)
打印结果:
{'LC': ['classmate', {'Name': 'Xlingling'}, '19'], 'HL': ['classmate', {'Name': 'Xlingling'}, '19'], 'GL': ['classmate', {'Name': 'Xlingling'}, '19']}

28 29 #字典循环 30 for i in dict: #i表示字典里的key 31 print(i,dict[i]) 32 35 #查找 36 dict1 = dict['stu1101'] #查找,但必须确认key值是存在,否则会报错 37 dict.get('stu1101') #查找,如果不存在key,则返回None 38 dict2 = 'stu1101' in dict #如果在字典内,则返回True,否则为Fasle 39 40 dict["stu1101"]="Will" #修改字典 41 dict["stu1104"]="Mark" #增加,如果key在字典中没有,则添加 42 43 #删除 44 del dict["stu1101"] #删除字典key和值 45 dict.popitem() #随机删除 46 dict.pop("stu1102") #删除指定key和值 47 ''' 48 #多层字典嵌套 49 ''' 50 dict ={ 51 "Europe":{ 52 "Denmark":["child","pipe"], 53 "Germany":["moto","Volk"], 54 "Net":["flower","girl"] 55 }, 56 "ASPA":{ 57 "China":["people","money"], 58 "Japan":["beautiful girl","Toyota-hot"] 59 }, 60 "Americam":{ 61 "North":["write","black"], 62 "East":["basketball","football"] 63 } 64 } 65 dict["Europe"]["Net"]=["wind","farmer"] #修改嵌套字典信息 66 print(dict)

 

posted on 2017-06-15 23:12  clv  阅读(156)  评论(0编辑  收藏  举报

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