communicate.py

async def communicate(self, stdin):
    stdout = []
    stderr = []
    
    async def receive_all_into(pipe, buf):
        while True:
            data = await pipe.receive_some(LIMIT)
            if not data:
                break
            buf.append(data)
            
    async with trio.open_nursery() as nursery:
        nursery.start_soon(receive_all_into, self.stdout, stdout)
        nursery.start_soon(receive_all_into, self.stderr, stderr)
        await self.stdin.send_all(stdin)
        
    return (b"".join(stdout), b"".join(stderr))