1from socket import inet_ntoa 2from struct import pack 3 4 5def calcDottedNetmask(mask): 6 bits = 0 7 for i in xrange(32-mask,32): 8 bits |= (1 << i) 9 packed_value = pack('!I', bits) 10 addr = inet_ntoa(packed_value) 11 return addr 12