How to Communicate with a Chess engine in Python?

Question

on win 7 i can communicate with a chess engine via commandline. Small Example Session with Stockfish on Win 7:

C:\\run\\Stockfish>stockfish-x64.exe
Stockfi         


        

Answer 1

You might want to use asyncio like python-chess does. See

engine.py

and the example from the documentation

import asyncio
import chess
import chess.engine

    async def main():
        transport, engine = await chess.engine.popen_uci("/usr/bin/stockfish")

        board = chess.Board()
        while not board.is_game_over():
            result = await engine.play(board, chess.engine.Limit(time=0.1))
            board.push(result.move)

        await engine.quit()

    asyncio.set_event_loop_policy(chess.engine.EventLoopPolicy())
    asyncio.run(main())

Answer 2

You've got a deadlock: the subprocess is waiting for input, while your program is waiting for it to output more lines in

for line in engine.stdout:
    print(line.strip())

This loop only stops when the subprocess closes its stdout.