def 
ip_to_num(ip):
    
ip
=
[
int
(x) 
for 
x 
in 
ip.split(
'.'
)]
    
return 
ip[
0
] <<
24 
| ip[
1
]<<
16 
| ip[
2
]<<
8 
|ip[
3
]
def 
num_to_ip(num):
    
return 
'%s.%s.%s.%s' 
%
( (num & 
0xff000000
) >>
24
,
                            
(num & 
0x00ff0000
) >>
16
,
                            
(num & 
0x0000ff00
) >>
8
,
                            
num & 
0x000000ff 
)