import urllib2

import cassette

with cassette.play("data/responses.yaml"):

    # If the request is not already stored in responses.yaml, cassette
    # will request the URL and store its response in the file.
    r = urllib2.urlopen("http://www.internic.net/domain/named.root")

    # This time, the request response must be in the file. The external
    # request is not made. cassette retrieves the response from the
    # file.
    r = urllib2.urlopen("http://www.internic.net/domain/named.root")

assert "A.ROOT-SERVERS.NET" in r.read(10000)