简单的获取网页样式元素（装饰器实现）

 1 import urllib.request
 2 import re
 3 #判断传入的地址是否有效
 4 def set_url(func):    #func=net_url
 5     def inner1(*args,**kwargs):
 6         if  re.match('^http.*[cn,com]$',args[0])!=None:
 7            f=func(*args,**kwargs)
 8            if len(f)>0:
 9                with open('net.txt','w+',encoding='utf-8')as fw:
10                    fw.write(f)
11                return f
12         else:
13             return '请输入正确的地址'
14     return inner1
15 #页面保存到文件中
16 def save_url(func):     #inner1
17     def inner(*args,**kwargs):
18         with open('net.txt','r+',encoding='utf-8') as f:
19             if len(f.readline())!=0:
20                 fr=f.read()
21                 print(fr)
22                 return '这是缓存的文件'
23             else:
24               fc=func(*args,**kwargs)
25               return fc
26     return inner
27 @save_url
28 @set_url
29 def net_url(gurl):
30 
31     request=urllib.request.Request(gurl)
32     repsonse=urllib.request.urlopen(request)
33     data=repsonse.read()
34     data=data.decode('utf-8')
35     return data
36 
37 url=input("请输入要获取的网页地址>>>")
38 ret=net_url(url)    #inner1               inner
39 print(ret)