增：
In [1]: info = {"name":"xiaoyafei","age":"18"}
In [2]: info["addr"] = "henan"
In [3]: info
Out[3]: {‘addr‘: ‘henan‘, ‘name‘: ‘xiaoyafei‘, ‘age‘: ‘18‘}
删：
In [4]: info
Out[4]: {‘addr‘: ‘henan‘, ‘name‘: ‘xiaoyafei‘, ‘age‘: ‘18‘}
In [5]: del info["age"]
In [6]: info
Out[6]: {‘addr‘: ‘henan‘, ‘name‘: ‘xiaoyafei‘}
改：
In [7]: info
Out[7]: {‘addr‘: ‘henan‘, ‘name‘: ‘xiaoyafei‘}
In [8]: info["name"] = "xiaobaba" #如果key存在则修改，不存在则是添加
In [9]: info
Out[9]: {‘addr‘: ‘henan‘, ‘name‘: ‘xiaobaba‘}
查：
In [10]: info
Out[10]: {‘addr‘: ‘henan‘, ‘name‘: ‘xiaobaba‘}
In [11]: info.get("addr")
Out[11]: ‘henan‘
In [12]: info.get("age")