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