zoukankan      html  css  js  c++  java
  • 字典的基本用法

    user_info={"name":"wang","age":"26","gender":"man"}
    #我们用键值对来表示
    key:name,age,gender
    value:wang,26,man

    #清空字典

    user_info={"name":"wang","age":"26","gender":"man"}
    user_info.clear()
    print(user_info)
    #输出:{}

    # 通过键获得值

    user_info={"name":"wang","age":"26","gender":"man"}
    str1= user_info.get("name")
    print(str1)
    #输出:wang

    # 获得字典里面内容以列表表示

    user_info={"name":"wang","age":"26","gender":"man"}
    str1= user_info.items()
    print(str1)
    #输出:dict_items([('name', 'wang'), ('gender', 'man'), ('age', '26')])

    #获得字典里面所有键值 列表表示

    user_info={"name":"wang","age":"26","gender":"man"}
    str1= user_info.keys()
    print(str1)
    #输出:dict_keys(['name', 'gender', 'age'])

    #获得字典里面所有的键值表示

    user_info={"name":"wang","age":"26","gender":"man"}
    str1= user_info.values()
    print(str1)
    #输出:dict_values(['26', 'wang', 'man'])

    #增加

    user_info={"name":"wang","age":"26","gender":"man"}
    user_info["salary"]="2000"
    print(user_info)
    #{'name': 'wang', 'age': '26', 'gender': 'man', 'salary': '2000'}

    #查找

    user_info={"name":"wang","age":"26","gender":"man"}
    print("age" in  user_info.keys())
    #输出:True

    #删除

    user_info={"name":"wang","age":"26","gender":"man"}
    ret=user_info.pop("name")
    print(ret)
    #返回 wang 有放回值
    dic={"k1":11,"k2":22,"k3":33}
    del dic["k2"]
    print(dic)
    #输出{'k1': 11, 'k3': 33} 无返回值
    
    #如果删除的key不在字典中那么就会报错
    dic={"k1":11,"k2":22,"k3":33}
    del dic["k5"]
    print(dic)
    #输出:KeyError: 'k5'

    update(self, E=None, **F): 更新字典(个人感觉没什么卵用)

    dic={"k1":11,"k2":22,"k3":33}
    dic.update({"k1":11,"k2":22,"k3":33,"k4":55})
    print(dic)
    #输出:{'k2': 22, 'k4': 55, 'k3': 33, 'k1': 11}
  • 相关阅读:
    软工第二次作业
    Internet: gmail on ubuntu
    English: assign
    Github: write blog by github
    Linux: left shift key not working on ubuntu18.04
    Using Doxygen to generate code documents
    Cpp: object lifetime
    Cpp: struct constructor
    Cpp: pass by reference
    HLS Stream Library
  • 原文地址:https://www.cnblogs.com/ricemi/p/7905811.html
Copyright © 2011-2022 走看看