我最近遇到了省略号(...)，它在aiohttp code中的函数参数中使用，然后在该函数的主体中使用:
def make_mocked_request(method, path, headers=None, *,
match_info=sentinel,
version=HttpVersion(1, 1), closing=False,
app=None,
writer=sentinel,
protocol=sentinel,
transport=sentinel,
payload=sentinel,
sslcontext=None,
client_max_size=1024**2,
loop=...):
"""Creates mocked web.Request testing purposes.
Useful in unit tests, when spinning full web server is overkill or
specific conditions and errors are hard to trigger.
"""
task = mock.Mock()
if loop is ...:
loop = mock.Mock()
loop.create_future.return_value = ()
你能解释一下python 3的这个新特性吗？