Get ip v4 address on OS X or Linux using python and ip command

get_ip.py

from subprocess import check_output
import sys
import re

if sys.platform == 'darwin':
    ip0 = check_output(['ip', 'addr', 'show', 'en0'])
else:
    ip0 = check_output(['ip', 'addr', 'show', 'eth0'])

ip1 = re.search('inet\s.*(?=/)', str(ip0))
ip2 = re.search('\d+\.\d+\.\d+\.\d+', str(ip1.group()))

ip = ip2.group()

print(ip0, ip1, ip2, ip, sep='\n')

"""
b'en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500\n\tether 6c:40:08:bc:64:7c\n\tinet6 fe80::6e40:8ff:febc:647c/64 scopeid 0x4\n\tinet 192.168.8.100/24 brd 192.168.8.255 en0\n'
<_sre.SRE_Match object; span=(152, 170), match='inet 192.168.8.100'>
<_sre.SRE_Match object; span=(5, 18), match='192.168.8.100'>
192.168.8.100
"""

get_ip_2.py

# Thanks https://www.chenyudong.com/archives/python-get-local-ip-graceful.html
import socket
 
def get_host_ip():
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        s.connect(('8.8.8.8', 80))
        ip = s.getsockname()[0]
    finally:
        s.close()
    return ip