'Yields the redirected URL, or None.'

@property
def redirect(self, timeout=10):

    if (self.__dict__['_redirect'] is None):
        try:
            r = u(self.open(timeout).geturl())
        except URLError:
            r = None
        self.__dict__['_redirect'] = (((r != self.string) and r) or '')
    return (self.__dict__['_redirect'] or None)
