问题
What is the way to do urlopen in python such that even if the underlying machine has ipv6 networking enabled, the request is sent via ipv4 instead of ipv6?
回答1:
I had a look into the source code. Unfortunately, urllib.urlopen() seems to use httplib.HTTP(), which doesn't even allow setting a source address.
urllib2.urlopen() uses httplib.HTTPConnection() which you could inherit from and create a class which by default sets a source address '0.0.0.0' instead of ''. Then you could somehow inject that new overridden class into the urllib2 stuff by creating a "new" HTTPHandler() (look how it's done in urllib2.py) and a new opener which you build_opener() and/or install_opener().
Sorry for not being very exact, but I never have done such a thing and don't know exactly how that works.
来源：https://stackoverflow.com/questions/11231244/how-to-do-urlopen-over-ipv4-by-default