Checking for IP addresses

Question

Are there any existing libraries to parse a string as an ipv4 or ipv6 address, or at least identify whether a string is an IP address (of either sort)?

Answer 1

Yes, there is ipaddr module, that can you help to check if a string is a IPv4/IPv6 address, and to detect its version.

import ipaddr
import sys

try:
   ip = ipaddr.IPAddress(sys.argv[1])
   print '%s is a correct IP%s address.' % (ip, ip.version)
except ValueError:
   print 'address/netmask is invalid: %s' % sys.argv[1]
except:
   print 'Usage : %s  ip' % sys.argv[0]

But this is not a standard module, so it is not always possible to use it. You also try using the standard socket module:

import socket

try:
    socket.inet_aton(addr)
    print "ipv4 address"
except socket.error:
    print "not ipv4 address"

For IPv6 addresses you must use socket.inet_pton(socket.AF_INET6, address).

I also want to note, that inet_aton will try to convert (and really convert it) addresses like 10, 127 and so on, which do not look like IP addresses.

Answer 2

For IPv4, you can use

socket.inet_aton(some_string)

If it throws an exception, some_string is not a valid ip address

For IPv6, you can use:

socket.inet_pton(socket.AF_INET6, some_string)

Again, it throws an exception, if some_string is not a valid address.

Answer 3

IPv4 + IPv6 solution relying only on standard library. Returns 4 or 6 or raises ValueError.

try:
    # Python 3.3+
    import ipaddress

    def ip_kind(addr):
        return ipaddress.ip_address(addr).version

except ImportError:
    # Fallback
    import socket

    def ip_kind(addr):
        try:
            socket.inet_aton(addr)
            return 4
        except socket.error: pass
        try:
            socket.inet_pton(socket.AF_INET6, addr)
            return 6
        except socket.error: pass
        raise ValueError(addr)

Answer 4

You can use the netaddr library. It has valid_ipv4/valid_ipv6 methods:

import netaddr
if netaddr.valid_ipv4(str_ip) is True:
    print("IP is IPv4")
else:
    if netaddr.valid_ipv6(str_ip) is True:
        print("IP is IPv6")

Answer 5

ipaddr -- Google's IP address manipulation package.

Note that a proposal to include a revised version of the package in the Python standard library has recently been accepted (see PEP 3144).

Answer 6

Try

apt-get install python-ipaddr

or get the source code from here

Answer 7

If you know for sure that the address is valid and only trying to decide whether it is ipv4 or ipv6, wouldn't it be sufficient to do just:

if ":" in address:
    print("Ipv6")
else:
    print("Ipv4")

Answer 8

I prefer ip_interface because it handles situations both with and without prefix mask, for example, both "10.1.1.1/24" as well as simply "10.1.1.1". Needless to say, works for both v4 as well as v6

from ipaddress import ip_interface
ip_interface("10.1.1.1/24").ip
ip_interface("10.1.1.1/24").ip.version
ip_interface("10.1.1.1").ip
ip_interface("10.1.1.1").ip.version