'The URL through the host (no path)'

@property
def host_url(self):

    e = self.environ
    scheme = e.get('wsgi.url_scheme')
    url = (scheme + '://')
    host = e.get('HTTP_HOST')
    if (host is not None):
        if (':' in host):
            (host, port) = host.split(':', 1)
        else:
            port = None
    else:
        host = e.get('SERVER_NAME')
        port = e.get('SERVER_PORT')
    if (scheme == 'https'):
        if (port == '443'):
            port = None
    elif (scheme == 'http'):
        if (port == '80'):
            port = None
    url += host
    if port:
        url += (':%s' % port)
    return url
