http.py 文件源码

def __init__(self, loop=None, requests_policy=RequestsPolicy.asynchronous):
        self.loop = loop if loop is not None else asyncio.get_event_loop()
        self.requests_policy = requests_policy

        # Build our default headers
        fmt = '{0}/{1} ({2}) Python/{3.major}.{3.minor}.{3.micro} aiohttp/{4} requests/{5}'
        user_agent = fmt.format(__title__, __version__, __url__, version_info, aiohttp.__version__, requests.__version__)
        self.default_headers = {'User-Agent': user_agent}

        # Prepare the sessions
        self.session_async = aiohttp.ClientSession(loop=loop, headers=self.default_headers)
        self.session_sync = requests.Session()
        self.session_sync.headers = self.default_headers