code: def bin(self):
          
          bits = self.v == 4 and 32 or 128
          return bin(self.ip).split('b')[1].rjust(bits, '0')
docs: Full-length binary representation of the IP address.
  
          >>> ip = IP("127.0.0.1")
          >>> print(ip.bin())
          01111111000000000000000000000001