Force requests to use IPv4 / IPv6

Question

How to force the requests library to use a specific internet protocol version for a get request? Or can this be achieved better with another method in Python? I

Answer 1

I took a similar approach to https://stackoverflow.com/a/33046939/5059062, but instead patched out the part in socket that makes DNS requests so it only does IPv6 or IPv4, for every request, which means this can be used in urllib just as effectively as in requests.

This might be bad if your program also uses unix pipes and other such things, so I urge caution with monkeypatching.

import requests
import socket
from unittest.mock import patch
import re

orig_getaddrinfo = socket.getaddrinfo
def getaddrinfoIPv6(host, port, family=0, type=0, proto=0, flags=0):
    return orig_getaddrinfo(host=host, port=port, family=socket.AF_INET6, type=type, proto=proto, flags=flags)

def getaddrinfoIPv4(host, port, family=0, type=0, proto=0, flags=0):
    return orig_getaddrinfo(host=host, port=port, family=socket.AF_INET, type=type, proto=proto, flags=flags)

with patch('socket.getaddrinfo', side_effect=getaddrinfoIPv6):
    r = requests.get('http://ip6.me')
    print('ipv6: '+re.search(r'\+3>(.*?)(.*?)

and without requests:

import urllib.request
import socket
from unittest.mock import patch
import re

orig_getaddrinfo = socket.getaddrinfo
def getaddrinfoIPv6(host, port, family=0, type=0, proto=0, flags=0):
    return orig_getaddrinfo(host=host, port=port, family=socket.AF_INET6, type=type, proto=proto, flags=flags)

def getaddrinfoIPv4(host, port, family=0, type=0, proto=0, flags=0):
    return orig_getaddrinfo(host=host, port=port, family=socket.AF_INET, type=type, proto=proto, flags=flags)

with patch('socket.getaddrinfo', side_effect=getaddrinfoIPv6):
    r = urllib.request.urlopen('http://ip6.me')
    print('ipv6: '+re.search(r'\+3>(.*?)(.*?)

Tested in 3.5.2