Traceback (most recent call last):


 "/usr/local/lib/python3.7/asyncio/events.py", line 88, in _run

self._context.run(self._callback, *self._args)


 "/usr/local/lib/python3.7/site-packages/aiohttp/web_ws.py", line 102, in _send_heartbeat

self._loop.create_task(self._writer.ping())
# type: ignore
AttributeError: 'NoneType' object has no attribute 'ping'

Traceback (most recent call last):


 "d:/Python/WS/PyTorch/Deep-Reinforcement-Learning-Hands-On/Chapter10/02_pong_a2c.py", line 159, in <module>

tb_tracker.track("advantage",
adv_v, step_idx)


 "D:\Python\WinPython3670\python-3.6.7.amd64\lib\site-packages\ptan\common\utils.py", line 329, in track

self.writer.add_scalar(param_name, np.mean(data), iter_index)


 "D:\Python\WinPython3670\python-3.6.7.amd64\lib\site-packages\numpy\core\fromnumeric.py", line 2957, in mean

out=out, **kwargs)


 "D:\Python\WinPython3670\python-3.6.7.amd64\lib\site-packages\numpy\core\_methods.py", line 80, in _mean

ret = ret.dtype.type(ret / rcount)
AttributeError: 'torch.dtype' object has no attribute 'type'