Python: Subnetmaske, CIDR, Anzahl Hosts rechnen

Hostanzahl -> CIDR

>>> import math
>>> hosts = 256
>>> cidr = 32-int(math.log(int(hosts), 2))
>>> print(cidr)
24

CIDR -> Hostanzahl

>>> import math
>>> cidr = 24
>>> hosts = int(math.pow(2,(32-int(cidr))))
>>> print(hosts)
256

CIDR -> Subnetmask

>>> cidr = 24
>>> mask = ".".join([str((((1 << 32) - 1) << (32 - cidr) >> i) & 255) for i in reversed(range(0, 32, 8))])
>>> print(mask)
255.255.255.0

Subnetmask -> CIDR

>>> mask = "255.255.255.0"
>>> cidr = sum((bin(x).count('1') for x in [int(x) for x in mask.split(".")]))
>>> print(cidr)
24