Use urllib in python to fetch IPv6 URL with FQDN

I want to fetch an IPv6 page with urllib. Works with square brack IPv6 notation but I have no clue how to (easily) convince python to do an IPv6 request when I give it the FQDN Like the below ip is: https://www.dslreports.com/whatismyip

from sys import version_info

PY3K = version_info >= (3, 0)

if PY3K:
    import urllib.request as urllib
else:
    import urllib2 as urllib

url = None
opener = urllib.build_opener()
opener.addheaders = [('User-agent',
     "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36")]
url = opener.open("http://[2607:fad0:3706:1::1000]/whatismyip", timeout=3)
content = url.read()