How do you determine if an IP address is private, in Python?

Since Python 3.3 there is an ipaddress module in the stdlib that you can use.

>>> import ipaddress>>> ipaddress.ip_address('192.168.0.1').is_privateTrue

If using Python 2.6 or higher I would strongly recommend to use a backport of this module.

Check out the IPy module. If has a function iptype() that seems to do what you want:

>>> from IPy import IP>>> ip = IP('127.0.0.0/30')>>> ip.iptype()'PRIVATE'

You can check that yourself usinghttps://www.rfc-editor.org/rfc/rfc1918 and https://www.rfc-editor.org/rfc/rfc3330. If you have 127.0.0.1 you just need to & it with the mask (lets say 255.0.0.0) and see if the value matches any of the private network's network address. So using inet_pton you can do: 127.0.0.1 & 255.0.0.0 = 127.0.0.0

Here is the code that illustrates that:

from struct import unpackfrom socket import AF_INET, inet_ptondef lookup(ip):    f = unpack('!I',inet_pton(AF_INET,ip))[0]    private = (        [ 2130706432, 4278190080 ], # 127.0.0.0,   255.0.0.0   https://www.rfc-editor.org/rfc/rfc3330        [ 3232235520, 4294901760 ], # 192.168.0.0, 255.255.0.0 https://www.rfc-editor.org/rfc/rfc1918        [ 2886729728, 4293918720 ], # 172.16.0.0,  255.240.0.0 https://www.rfc-editor.org/rfc/rfc1918        [ 167772160,  4278190080 ], # 10.0.0.0,    255.0.0.0   https://www.rfc-editor.org/rfc/rfc1918    )     for net in private:        if (f & net[1]) == net[0]:            return True    return False# exampleprint(lookup("127.0.0.1"))print(lookup("192.168.10.1"))print(lookup("10.10.10.10"))print(lookup("172.17.255.255"))# outputs True True True True

another implementation is to compute the int values of all private blocks:

from struct import unpackfrom socket import AF_INET, inet_ptonlookup = "127.0.0.1"f = unpack('!I',inet_pton(AF_INET,lookup))[0]private = (["127.0.0.0","255.0.0.0"],["192.168.0.0","255.255.0.0"],["172.16.0.0","255.240.0.0"],["10.0.0.0","255.0.0.0"])for net in private:    mask = unpack('!I',inet_aton(net[1]))[0]    p = unpack('!I',inet_aton(net[0]))[0]    if (f & mask) == p:        print lookup + " is private"