Help Required with:- chess.engine --> NotImplementedError

[rpatapa]

>python -V

Python 3.10.16

>>> pip show chess

Name: chess
Version: 1.11.1

The following statements are running into a NotImplementedError. Am I not using the syntax properly? Even if I use the path to Stockfish exe also, the same error is reported. What should I correct? Please suggest. I could not test this with other engines. Is this a stockfish error? Or is this a syntax error? Or is this a bug? I see some similar issue discussion at #725 but I am not sure if both are same.

>>> import chess.engine
>>> engine = chess.engine.SimpleEngine.popen_uci("stockfish")
---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
Cell In[9], line 1
----> 1 engine = chess.engine.SimpleEngine.popen_uci("stockfish")

File ~\miniconda3\envs\myve\lib\site-packages\chess\engine.py:3052, in SimpleEngine.popen_uci(cls, command, timeout, debug, setpgrp, **popen_args)
   3046 @classmethod
   3047 def popen_uci(cls, command: Union[str, List[str]], *, timeout: Optional[float] = 10.0, debug: Optional[bool] = None, setpgrp: bool = False, **popen_args: Any) -> SimpleEngine:
   3048     """
   3049     Spawns and initializes a UCI engine.
   3050     Returns a :class:`~chess.engine.SimpleEngine` instance.
   3051     """
-> 3052     return cls.popen(UciProtocol, command, timeout=timeout, debug=debug, setpgrp=setpgrp, **popen_args)

File ~\miniconda3\envs\myve\lib\site-packages\chess\engine.py:3044, in SimpleEngine.popen(cls, Protocol, command, timeout, debug, setpgrp, **popen_args)
   3041         simple_engine.close()
   3042     await simple_engine.shutdown_event.wait()
-> 3044 return run_in_background(background, name=f"{cls.__name__} (command={command!r})", debug=debug)

File ~\miniconda3\envs\myve\lib\site-packages\chess\engine.py:77, in run_in_background(coroutine, name, debug)
     74         future.set_exception(exc)
     76 threading.Thread(target=background, name=name).start()
---> 77 return future.result()

File ~\miniconda3\envs\myve\lib\concurrent\futures\_base.py:458, in Future.result(self, timeout)
    456     raise CancelledError()
    457 elif self._state == FINISHED:
--> 458     return self.__get_result()
    459 else:
    460     raise TimeoutError()

File ~\miniconda3\envs\myve\lib\concurrent\futures\_base.py:403, in Future.__get_result(self)
    401 if self._exception:
    402     try:
--> 403         raise self._exception
    404     finally:
    405         # Break a reference cycle with the exception in self._exception
    406         self = None

File ~\miniconda3\envs\myve\lib\site-packages\chess\engine.py:71, in run_in_background.<locals>.background()
     69 def background() -> None:
     70     try:
---> 71         asyncio.run(coroutine(future), debug=debug)
     72         future.cancel()
     73     except Exception as exc:

File ~\miniconda3\envs\myve\lib\asyncio\runners.py:44, in run(main, debug)
     42     if debug is not None:
     43         loop.set_debug(debug)
---> 44     return loop.run_until_complete(main)
     45 finally:
     46     try:

File ~\miniconda3\envs\myve\lib\asyncio\base_events.py:649, in BaseEventLoop.run_until_complete(self, future)
    646 if not future.done():
    647     raise RuntimeError('Event loop stopped before Future completed.')
--> 649 return future.result()

File ~\miniconda3\envs\myve\lib\site-packages\chess\engine.py:3032, in SimpleEngine.popen.<locals>.background(future)
   3031 async def background(future: concurrent.futures.Future[SimpleEngine]) -> None:
-> 3032     transport, protocol = await Protocol.popen(command, setpgrp=setpgrp, **popen_args)
   3033     threading.current_thread().name = f"{cls.__name__} (pid={transport.get_pid()})"
   3034     simple_engine = cls(transport, protocol, timeout=timeout)

File ~\miniconda3\envs\myve\lib\site-packages\chess\engine.py:1212, in Protocol.popen(cls, command, setpgrp, **popen_args)
   1208         else:
   1209             # Before Python 3.11
   1210             popen_args["start_new_session"] = True
-> 1212 return await asyncio.get_running_loop().subprocess_exec(cls, *command, **popen_args)

File ~\miniconda3\envs\myve\lib\asyncio\base_events.py:1681, in BaseEventLoop.subprocess_exec(self, protocol_factory, program, stdin, stdout, stderr, universal_newlines, shell, bufsize, encoding, errors, text, *args, **kwargs)
   1679     debug_log = f'execute program {program!r}'
   1680     self._log_subprocess(debug_log, stdin, stdout, stderr)
-> 1681 transport = await self._make_subprocess_transport(
   1682     protocol, popen_args, False, stdin, stdout, stderr,
   1683     bufsize, **kwargs)
   1684 if self._debug and debug_log is not None:
   1685     logger.info('%s: %r', debug_log, transport)

File ~\miniconda3\envs\myve\lib\asyncio\base_events.py:498, in BaseEventLoop._make_subprocess_transport(self, protocol, args, shell, stdin, stdout, stderr, bufsize, extra, **kwargs)
    494 async def _make_subprocess_transport(self, protocol, args, shell,
    495                                      stdin, stdout, stderr, bufsize,
    496                                      extra=None, **kwargs):
    497     """Create subprocess transport."""
--> 498     raise NotImplementedError

NotImplementedError: 

[niklasf]

Are you running this in Jupyter or a similar environment?

[rpatapa]

in an environment created in miniconda on windows laptop

[niklasf]

The Cell In[9] in the output makes me think that it's not just normal Python, but maybe IPython? There's been some bugs with IPython breaking asyncio, e.g. jupyter/notebook#5907.

Is this the latest version available for your system?

[rpatapa]

Possibly..

One observation: I was using Conda installation and was able to execute this without any errors earlier. Recently, I uninstalled conda completely (for some reason) and installed light weigth miniconda and since then I am facing this issue with the very basic statement of calling the chess engine.

Just now, I installed Thonny and I am able to execute this basic statement and the main program that I wrote using chess package without any errors.

So, I tend to agree with you and suspect some issue with miniconda enviroment. For now, I am good because I have alternate method to execute the code. But the issue persists, if anybody wants to pursue further. For now, this can be considered closed, from myside!

Thank you very much for the insights and have a good weekend!