Python DeprecationWarning in Exchange.close()

• OS: macOS 11.2
• Programming Language version: Python 3.9.1
• CCXT version: ccxtpro==0.5.51

Reproduction steps

Run this script with python3 -W default script.py.

import asyncio

from ccxtpro import ftx


async def main() -> None:
    client = ftx()
    ticker = await client.watch_ticker("BTC-PERP")
    print(ticker)
    await client.close()

    print("Closing")

if __name__ == '__main__':
    asyncio.run(main())

Results

A DeprecationWarning is triggered:

.venv/bin/python -W default script.py
.venv/lib/python3.9/site-packages/ccxtpro/base/exchange.py:178: DeprecationWarning: The explicit passing of coroutine objects to asyncio.wait() is deprecated since Python 3.8, and scheduled for removal in Python 3.11.
  await asyncio.wait([client.close() for client in self.clients.values()], return_when=asyncio.ALL_COMPLETED)
{'symbol': 'BTC-PERP', 'timestamp': 1612340929250, 'datetime': '2021-02-03T08:28:49.250Z', 'high': None, 'low': None, 'bid': 36106.0, 'bidVolume': 0.0831, 'ask': 36107.0, 'askVolume': 18.6912, 'vwap': None, 'open': None, 'close': 36108.0, 'last': 36108.0, 'previousClose': None, 'change': None, 'percentage': None, 'average': None, 'baseVolume': None, 'quoteVolume': None, 'info': {'bid': 36106.0, 'ask': 36107.0, 'bidSize': 0.0831, 'askSize': 18.6912, 'last': 36108.0, 'time': 1612340929.2509072}}
Closing

Possible solution

The problem is in the Exchange.close() method.

Replacing asyncio.wait() with asyncio.gather() resolves the problem.

[frosty00]

@pietrodn I can confirm I am able to reproduce the bug, will need a bit more time to solve it

[pietrodn]

Hello @kroitor, I just tested with ccxtpro==0.6.12, ccxt==1.43.82 and confirm that the original issue is gone. Thank you! 🚀

However I see another warning when executing the script with python -X dev (to enable all default warnings and asyncio debug mode).

I can open another issue though, it looks like a separate problem.

.venv/bin/python -W default -X dev "/Users/pd/Library/Application Support/JetBrains/PyCharm2020.3/scratches/scratch.py"
{'symbol': 'BTC-PERP', 'timestamp': 1616272962356, 'datetime': '2021-03-20T20:42:42.356Z', 'high': None, 'low': None, 'bid': 58439.0, 'bidVolume': 0.9143, 'ask': 58440.0, 'askVolume': 0.2803, 'vwap': None, 'open': None, 'close': 58440.0, 'last': 58440.0, 'previousClose': None, 'change': None, 'percentage': None, 'average': None, 'baseVolume': None, 'quoteVolume': None, 'info': {'bid': 58439.0, 'ask': 58440.0, 'bidSize': 0.9143, 'askSize': 0.2803, 'last': 58440.0, 'time': 1616272962.3567138}}
Closing
/Users/pd/.pyenv/versions/3.9.1/lib/python3.9/asyncio/selector_events.py:704: ResourceWarning: unclosed transport <_SelectorSocketTransport fd=7>
  _warn(f"unclosed transport {self!r}", ResourceWarning, source=self)
ResourceWarning: Enable tracemalloc to get the object allocation traceback
.venv/lib/python3.9/site-packages/aiohttp/client_reqrep.py:811: ResourceWarning: Unclosed response <ClientResponse(wss://ftx.com/ws) [101 Switching Protocols]>
<CIMultiDictProxy('Date': 'Sat, 20 Mar 2021 20:42:42 GMT', 'Connection': 'upgrade', 'Upgrade': 'websocket', REDACTED)>

  _warnings.warn(f"Unclosed response {self!r}", ResourceWarning, **kwargs)
ResourceWarning: Enable tracemalloc to get the object allocation traceback
Unclosed response
client_response: <ClientResponse(wss://ftx.com/ws) [101 Switching Protocols]>
<CIMultiDictProxy('Date': 'Sat, 20 Mar 2021 20:42:42 GMT', 'Connection': 'upgrade', 'Upgrade': 'websocket', REDACTED)>

source_traceback: Object created at (most recent call last):
  File "/Users/pd/Library/Application Support/JetBrains/PyCharm2020.3/scratches/scratch.py", line 15, in <module>
    asyncio.run(main())
  File "/Users/pd/.pyenv/versions/3.9.1/lib/python3.9/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/Users/pd/.pyenv/versions/3.9.1/lib/python3.9/asyncio/base_events.py", line 629, in run_until_complete
    self.run_forever()
  File "/Users/pd/.pyenv/versions/3.9.1/lib/python3.9/asyncio/base_events.py", line 596, in run_forever
    self._run_once()
  File "/Users/pd/.pyenv/versions/3.9.1/lib/python3.9/asyncio/base_events.py", line 1882, in _run_once
    handle._run()
  File "/Users/pd/.pyenv/versions/3.9.1/lib/python3.9/asyncio/events.py", line 80, in _run
    self._context.run(self._callback, *self._args)
  File ".venv/lib/python3.9/site-packages/aiohttp/client.py", line 1117, in __aenter__
    self._resp = await self._coro
  File ".venv/lib/python3.9/site-packages/aiohttp/client.py", line 754, in _ws_connect
    resp = await self.request(
  File ".venv/lib/python3.9/site-packages/aiohttp/client.py", line 542, in _request
    resp = await req.send(conn)
  File ".venv/lib/python3.9/site-packages/aiohttp/client_reqrep.py", line 674, in send
    self.response = response_class(
Process finished with exit code 0