添加

        xxx[新的key] = value

    删除

        del xx[key]

    修改

        xxx[已存在的key] = new_value

    查询

        xxx.get(key)

#### list 列表存储数据

In [4]: stu001 = ["alex",18,"北京"]

In [5]: print("%s的年龄是%d,家住在%s"%(stu001[0],stu001[1],stu001[2]))

alex的年龄是18,家住在北京

##### dict 字典存储数据

In [6]: #字典

In [7]: #info = {键:值，键:值}      key：value   键值对

In [8]: stu001 = {"name":"alex","age":18,"home":"beijing"}

In [12]: print("%s的年龄是%d,家在%s"%(stu001["name"],stu001["age"],stu001["home"]))

alex的年龄是18,家在beijing

########   增加  xxx[新的key] = value

In [1]: infor = {"name":"alex"}

In [2]: infor["age"] = 18

In [3]: infor

Out[3]: {'name': 'alex', 'age': 18}

In [4]: infor["QQ"] = 10086

In [5]: infor

Out[5]: {'QQ': 10086, 'name': 'alex', 'age': 18}

#########  删除  del xxx[已存在的key]

#########  删除  del xxx[不存在的key]  报错

In [8]: del infor["QQ"]

In [9]: infor

Out[9]: {'name': 'alex', 'age': 18}

In [10]: del infor["QQ"]

---------------------------------------------------------------------------

KeyError                                  Traceback (most recent call last)

<ipython-input-10-1c0f878ade5a> in <module>()

----> 1 del infor["QQ"]

KeyError: 'QQ'

#########  修改  xxx[已存在的key] = new_value

In [6]: infor["QQ"] = 8888

In [7]: infor

Out[7]: {'QQ': 8888, 'name': 'alex', 'age': 18}

#########  查询 不正确用法   infor["QQ"]

In [11]: infor

Out[11]: {'name': 'alex', 'age': 18}

In [12]: infor["name"]

Out[12]: 'alex'

In [13]: infor["age"]

Out[13]: 18

In [14]: infor["QQ"]

---------------------------------------------------------------------------

KeyError                                  Traceback (most recent call last)

<ipython-input-14-8398698e14db> in <module>()

----> 1 infor["QQ"]

KeyError: 'QQ'

######## 查询  标准用法   infor.get("QQ")

In [15]: infor.get("QQ")

In [16]: infor.get("name")

Out[16]: 'alex'

In [17]: infor.get("age")

Out[17]: 18