Problem D: IP地址合法性和网络类别检查

 1 def Islegal(a):
 2     ip = list(map(int,a))
 3     flag = 0 #标志是否合法
 4     if  0<=ip[0]<=255:
 5             if  0<=ip[1]<=255:
 6                 if 0 <= ip[2] <= 255:
 7                     if 0 <= ip[3] <= 255:
 8                         flag = 1
 9     if flag==0:
10         print("NO")
11         return
12     if ip[0]<=127:
13         print("A")
14         return
15     if 128<=ip[0]<=191:
16         print("B")
17         return
18     if 192<=ip[0]<=223:
19         print("C")
20         return
21     if 224<=ip[0]<=239:
22         print("D")
23         return
24     if 240 <= ip[0] <= 255:
25         print("E")
26         return
27 
28 def func():
29     while True:
30         #EOFError的作用就是执行到文件末尾然后抛出异常
31         #try...except捕捉到异常然后执行break语句终止循环
32         try:
33             a = input()
34             a = a.split('.',3)
35             Islegal(a)
36         except EOFError:
37             break
38 
39 
40 if __name__ == '__main__':
41     func()