介绍Python设置属性值方法setattr()和判断变量是否存在的方法

1.以属性名为变量的方式给一个对象添加属性

使用 setattr 方法

obj = SomeClass() key = 'key_name' val = 'key_value' setattr(obj, key, val) print(obj.key_name) 

示例：给报文字段赋值

from scapy.all import * layer = {"ether":"dst='33:33:00:01:00:02',src='00:0c:29:d9:98:c7'"} Ethernet_field = layer.setdefault('ether') ethernet = Ether(type=0x86dd) fields = dict(((lambda a:(a[0].strip("'"),a[1].strip("'"))) (field.split('=')) for field in Ethernet_field.split(','))) for key, val in fields.items(): setattr(ethernet, key, val) ethernet.show() 

输出

>>> ethernet.show() ###[ Ethernet ]### dst = 33:33:00:01:00:02 src = 00:0c:29:d9:98:c7 type = IPv6 

2.判断变量是否存在

三种方法：

• locals().keys()
• dir()
• vars()

ethernet = 'Ether' dhcpv6 = 'dhcpv6_solicit' message = ['ethernet','ip','udp','dhcpv6'] del_message = [] for layer_i, value in enumerate(message): if message[layer_i] not in locals().keys(): del_message.append(value) for m in del_message: message.remove(m) print(f'message:{message}') 

运行结果：

C:\Users\DELL>python3 test_locals.py message:['ethernet', 'dhcpv6']