[‘__class__‘, ‘__contains__‘, ‘__delattr__‘, ‘__delitem__‘, ‘__dir__‘, ‘__doc__‘, ‘__eq__‘, ‘__format__‘, ‘__ge__‘,
‘__getattribute__‘, ‘__getitem__‘, ‘__gt__‘, ‘__hash__‘, ‘__init__‘, ‘__iter__‘, ‘__le__‘, ‘__len__‘, ‘__lt__‘, ‘__ne__‘,
 ‘__new__‘, ‘__reduce__‘, ‘__reduce_ex__‘, ‘__repr__‘, ‘__setattr__‘, ‘__setitem__‘, ‘__sizeof__‘, ‘__str__‘,
 ‘__subclasshook__‘,
 ‘clear‘, ‘copy‘, ‘fromkeys‘, ‘get‘, ‘items‘, ‘keys‘, ‘pop‘, ‘popitem‘, ‘setdefault‘, ‘update‘, ‘values‘]
my_dict = {
    ‘user1‘:"zhangsan",
    ‘user2‘:"lisi",
    ‘user3‘:"wangermazi",
}
print(my_dict)
# {‘user2‘: ‘lisi‘, ‘user3‘: ‘wangermazi‘, ‘user1‘: ‘zhangsan‘},无序输出
my_dict[‘user4‘] = "xiaotaoqi"
print(my_dict)
# {‘user3‘: ‘wangermazi‘, ‘user4‘: ‘xiaotaoqi‘, ‘user2‘: ‘lisi‘, ‘user1‘: ‘zhangsan‘},增加
my_dict[‘user1‘] = "ZHANGSAN"
print(my_dict)
# {‘user3‘: ‘wangermazi‘, ‘user2‘: ‘lisi‘, ‘user4‘: ‘xiaotaoqi‘, ‘user1‘: ‘ZHANGSAN‘},修改

# 删除三法pop，del,popitem
my_dict.pop("user1")
print(my_dict)
# {‘user2‘: ‘lisi‘, ‘user3‘: ‘wangermazi‘, ‘user4‘: ‘xiaotaoqi‘}
del my_dict[‘user2‘]
print(my_dict)
# {‘user3‘: ‘wangermazi‘, ‘user4‘: ‘xiaotaoqi‘}

my_dict.popitem()
print(my_dict)
# {‘user2‘: ‘lisi‘, ‘user3‘: ‘wangermazi‘, ‘user1‘: ‘ZHANGSAN‘}

city = {
    ‘1‘:{
        ‘beijing‘:{
            ‘chaoyang‘:"xizhimen",
            ‘haidian‘:‘xibeiwang‘,
            ‘tongzhou‘:‘shuxi‘
        }
    },
    ‘2‘:"shanghai",
    ‘3‘:"liaoning"
}
print(city[‘1‘][‘beijing‘][‘haidian‘])
# xibeiwang
print(city.keys())
# dict_keys([‘1‘, ‘2‘, ‘3‘])
print(city.values())
# dict_values([{‘beijing‘: {‘haidian‘: ‘xibeiwang‘, ‘tongzhou‘: ‘shuxi‘, ‘chaoyang‘: ‘xizhimen‘}}, ‘shanghai‘, ‘liaoning‘])

print(city.items())
# dict_items([(‘3‘, ‘liaoning‘), (‘2‘, ‘shanghai‘), (‘1‘, {‘beijing‘: {‘tongzhou‘: ‘shuxi‘, ‘chaoyang‘: ‘xizhimen‘, ‘haidian‘: ‘xibeiwang‘}})])