用 python 获取本地/公网 ip 地址

一、Windows下2种方法:
1.
使用拨号上网的话，通常都有一个本地ip和一个外网ip，使用python能够很容易的获得这两个ip
使用gethostbyname和gethostbyname_ex两个函数能够实现
import socket
localIP = socket.gethostbyname(socket.gethostname())  #这个获得本地ip
print "local ip:%s "%localIP

ipList = socket.gethostbyname_ex(socket.gethostname())
for i in ipList:
    if i != localIP:
       print "external IP:%s"%i      
2.       
import socket

myname = socket.getfqdn(socket.gethostname())
myaddr = socket.gethostbyname(myname)

二、还有一种Linux下的方法能够用的是：

Uses the Linux SIOCGIFADDR ioctl to find the IP address associated with a network interface, given the name of that interface, e.g. "eth0". The address is returned as a string containing a dotted quad.

import socket
import fcntl
import struct

def get_ip_address(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    return socket.inet_ntoa(fcntl.ioctl(
        s.fileno(),
        0x8915,  # SIOCGIFADDR
        struct.pack('256s', ifname[:15])
    )[20:24])

>>> get_ip_address('lo')
'127.0.0.1'

>>> get_ip_address('eth0')
'38.113.228.130'

三、跨平台解决方案：

通用化，不用第三方包的代码：

def get_ip_address(ifname=None):
    if sys.platform == 'win32':
        return socket.getaddrinfo(socket.gethostname(), None, socket.AF_INET, socket.SOCK_DGRAM)[-1][4][0]
    else:
        import fcntl
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        return socket.inet_ntoa(fcntl.ioctl(
            s.fileno(),
            0x8915,  # SIOCGIFADDR
            struct.pack('256s', ifname[:15])
        )[20:24])

Refer：

[1] How do I determine all of my IP addresses when I have multiple NICs?

http://stackoverflow.com/questions/270745/how-do-i-determine-all-of-my-ip-addresses-when-i-have-multiple-nics