python之字典

字典:

  1 # 字典
  2 # dict
  3 # dict
  4 # dic = {
  5 #     "k1": 'v1',
  6 #     "k2": 'v2'
  7 # }
  8 # 1 根据序列，创建字典，并指定统一的值
  9 # v = dict.fromkeys(["k1",123,"999"],123)
 10 # print(v)
 11 
 12 # 2 根据Key获取值，key不存在时，可以指定默认值（None）
 13 # v = dic['k2']
 14 # print(v)
 15 # v = dic.get('k3',111111)
 16 # print(v)
 17 
 18 # 3 删除并获取值
 19 # dic = {
 20 #     "k1": 'v1',
 21 #     "k2": 'v2'
 22 # }
 23 # v = dic.pop('k3',90)
 24 # print(dic,v)
 25 # k,v = dic.popitem()
 26 # print(dic,k,v)
 27 
 28 # 4 设置值，
 29 # 已存在，不设置，获取当前key对应的值
 30 # 不存在，设置，获取当前key对应的值
 31 # dic = {
 32 #     "k1": 'v1',
 33 #     "k2": 'v2'
 34 # }
 35 # v = dic.setdefault('k1111','123')
 36 # print(dic,v)
 37 
 38 # 5 更新
 39 # dic = {
 40 #     "k1": 'v1',
 41 #     "k2": 'v2'
 42 # }
 43 # dic.update({'k1': '111111','k3': 123})
 44 # print(dic)
 45 # dic.update(k1=123,k3=345,k5="asdf")
 46 # print(dic)
 47 
 48 # 6 keys()  7 values()   8 items()   get   update
 49 ##########
 50 
 51 
 52 
 53 # 1、基本机构
 54 # info = {
 55 #     "k1": "v1", # 键值对
 56 #     "k2": "v2"
 57 # }
 58 #### 2 字典的value可以是任何值
 59 # info = {
 60 #     "k1": 18,
 61 #     "k2": True,
 62 #     "k3": [
 63 #         11,
 64 #         [],
 65 #         (),
 66 #         22,
 67 #         33,
 68 #         {
 69 #             'kk1': 'vv1',
 70 #             'kk2': 'vv2',
 71 #             'kk3': (11,22),
 72 #         }
 73 #     ],
 74 #     "k4": (11,22,33,44)
 75 # }
 76 # print(info)
 77 
 78 ####  3 布尔值(1,0)、列表、字典不能作为字典的key
 79 # info ={
 80 #     1: 'asdf',
 81 #     "k1": 'asdf',
 82 #     True: "123",
 83 #     # [11,22]: 123
 84 #     (11,22): 123,
 85 #     # {'k1':'v1'}: 123
 86 #
 87 # }
 88 # print(info)
 89 
 90 # 4 字典无序
 91 
 92 # info = {
 93 #     "k1": 18,
 94 #     "k2": True,
 95 #     "k3": [
 96 #         11,
 97 #         [],
 98 #         (),
 99 #         22,
100 #         33,
101 #         {
102 #             'kk1': 'vv1',
103 #             'kk2': 'vv2',
104 #             'kk3': (11,22),
105 #         }
106 #     ],
107 #     "k4": (11,22,33,44)
108 # }
109 # print(info)
110 
111 # 5、索引方式找到指定元素
112 # info = {
113 #     "k1": 18,
114 #     2: True,
115 #     "k3": [
116 #         11,
117 #         [],
118 #         (),
119 #         22,
120 #         33,
121 #         {
122 #             'kk1': 'vv1',
123 #             'kk2': 'vv2',
124 #             'kk3': (11,22),
125 #         }
126 #     ],
127 #     "k4": (11,22,33,44)
128 # }
129 # v = info['k1']
130 # print(v)
131 # v = info[2]
132 # print(v)
133 # v = info['k3'][5]['kk3'][0]
134 # print(v)
135 
136 # 6 字典支持 del 删除
137 # info = {
138 #     "k1": 18,
139 #     2: True,
140 #     "k3": [
141 #         11,
142 #         [],
143 #         (),
144 #         22,
145 #         33,
146 #         {
147 #             'kk1': 'vv1',
148 #             'kk2': 'vv2',
149 #             'kk3': (11,22),
150 #         }
151 #     ],
152 #     "k4": (11,22,33,44)
153 # }
154 # del info['k1']
155 #
156 # del info['k3'][5]['kk1']
157 # print(info)
158 
159 # 7 for循环
160 # dict
161 # info = {
162 #     "k1": 18,
163 #     2: True,
164 #     "k3": [
165 #         11,
166 #         [],
167 #         (),
168 #         22,
169 #         33,
170 #         {
171 #             'kk1': 'vv1',
172 #             'kk2': 'vv2',
173 #             'kk3': (11,22),
174 #         }
175 #     ],
176 #     "k4": (11,22,33,44)
177 # }
178 # for item in info:
179 #     print(item)
180 #
181 # for item in info.keys():
182 #     print(item)
183 
184 # for item in info.values():
185 #     print(item)
186 
187 # for item in info.keys():
188 #     print(item,info[item])
189 
190 # for k,v in info.items():
191 #     print(k,v)
192 
193 # True 1  False 0
194 # info ={
195 #     "k1": 'asdf',
196 #     True: "123",
197 #     # [11,22]: 123
198 #     (11,22): 123,
199 #     # {'k1':' v1'}: 123
200 #
201 # }
202 # print(info)
View Code

 

posted @ 2018-07-24 09:37  有猿人  阅读(284)  评论(0)  编辑  收藏  举报