t.py

@gen.croutine
def _proxy(method, *args, **kwargs):
    try:
        ret = yield method(*args, **kwargs)
    except ErrorYouWantCatch:
        # logging or something else
        ret = None
    raise gen.Return(ret)


@gen.coroutine
def get(self):
    http_client = AsyncHTTPClient()
    response1, response2 = yield [_proxy( http_client.fetch, url1),
                                  _proxy( http_client.fetch, url2)]