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  • python字典

    python 字典

    1.定义

    定义在大括号中的一组数据,以key-value键值对进行数据存储。

    dict_a = {"name":"jone","password":"redme"}
    print(type(dict_a))
    
    dict_b = {"192.168.1.1":[80,22,3306],"192.168.1.2":[1001,1002]}
    print(dict_b)
    
    dict_c = {
      "192.168.1.1":{
        "ssh_user":"root",
        "ssh_port":22,
        "ssh_password":"redme"
      }
    }
    print(type(dict_c))
    

    2.字典的常规操作

    (1.)获取数据

    dict_a = {"name":"jone","password":"redme"}
    print(dict_a["name"])
    print(dict_a.get("name"))
    

    (2.)添加数据

    dict_a = {"name":"jone","password":"redme"}
    dict_a["email"] = "xxx.com"
    print(dict_a)
    

    (3.) 修改数据

    dict_a = {"name":"jone","password":"redme"}
    dict_a["passwod"]="xxx.com"
    print(dict_a)
    

    (4.) 删除数据

    dict_a = {"name":"jone","password":"redme"}
    del dict_a["password"]
    print(dict_a)
    

    3.字典对象的操作方法

    (1.)keys() 以列表的形式返回字典中所有的键

    dict_a = {"name":"jone","password":"redme","level":30}
    print(dict_a.keys())
    

    (2.) values() 以列表的形式返回字典中的所有值

    dict_a = {"name":"shell","password":"redme","level":30}
    print(dict_a.values())
    

    (3.) items() 以列表的形式返回包含多个键值对组合的元组

    dict_a = {"name":"shell","password":"redme","level":30}
    print(dict_a.items())
    

    (4.) 通过for循环遍历字典

    # 通过dict_a.get() 获取值
    dict_a = {"name":"shell","password":"redme","level":30}
    for i in dict_a:
       print("key:%s,value:%s" %(i,dict_a.get(i)))
       
    # 通过dict_a.items()
    for k,v in dict_a.items():
        print("key:%s,value:%s" %(k,v))
    

    案例

    统计IP地址出现的次数

    # ip_number字典,key为IP,value为出现的次数
    ip_number = {}
    ip_list = ["192.168.1.1","192.168.1.2","192.168.1.3","192.168.1.3","192.168.1.1"]
    
    for ip in ip_list:
      if ip not in ip_number.keys()
         ip_number[ip] = 1
      else:
         ip_nmber[ip] = ip_number[ip] + 1
    for k,v in ip_number.items():
       print("ip:%s,次数:%s" % (k,v))
    
    【励志篇】: 古之成大事掌大学问者,不惟有超世之才,亦必有坚韧不拔之志。
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  • 原文地址:https://www.cnblogs.com/tomtellyou/p/15547502.html
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