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  • 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
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  • 原文地址:https://www.cnblogs.com/sqy-yyr/p/9358285.html
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