Import issue: AttributeError: 'NoneType' object has no attribute 'session'

ipykernel/comm/comm.py と matplotlib/backends/backend_nbagg.py の traceback パスから始め、次に VS Code から cerebro.plot() を再現します。この実行コンテキストを、issue で説明されている Jupyter 関連の動作と比較します。Done は、失敗が再現され、修正されているか、サポートされる実行コンテキストが明確に文書化されていることを意味します。

When import the package inside VScode I get an error:

<IPython.core.display.Javascript object>
<IPython.core.display.HTML object>
Traceback (most recent call last):
  File ".\dpseg.py", line 379, in <module>
    run()
  File ".\dpseg.py", line 320, in run
    cerebro.plot()
  File "C:\ProgramData\Anaconda3\lib\site-packages\backtrader\cerebro.py", line 996, in plot
    plotter.show()
  File "C:\ProgramData\Anaconda3\lib\site-packages\backtrader\plot\plot.py", line 817, in show
    self.mpyplot.show()
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\pyplot.py", line 272, in show
    return _show(*args, **kw)
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_nbagg.py", line 261, in show
    manager.show()
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_nbagg.py", line 90, in show
    self._create_comm()
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_nbagg.py", line 122, in _create_comm
    self.add_web_socket(comm)
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_webagg_core.py", line 433, in add_web_socket
    self.resize(w, h)
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_webagg_core.py", line 417, in resize
    self._send_event(
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_webagg_core.py", line 490, in _send_event
    s.send_json(payload)
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_nbagg.py", line 199, in send_json
    self.comm.send({'data': json.dumps(content)})
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\ipykernel\comm\comm.py", line 122, in send
    self._publish_msg('comm_msg',
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\ipykernel\comm\comm.py", line 66, in _publish_msg
    self.kernel.session.send(self.kernel.iopub_socket, msg_type,
AttributeError: 'NoneType' object has no attribute 'session'
Error in atexit._run_exitfuncs:
Traceback (most recent call last):
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\_pylab_helpers.py", line 72, in destroy_all
    manager.destroy()
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_nbagg.py", line 126, in destroy
    self._send_event('close')
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_webagg_core.py", line 490, in _send_event
    s.send_json(payload)
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\matplotlib\backends\backend_nbagg.py", line 199, in send_json
    self.comm.send({'data': json.dumps(content)})
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\ipykernel\comm\comm.py", line 122, in send
    self._publish_msg('comm_msg',
  File "C:\Users\Mislav\AppData\Roaming\Python\Python38\site-packages\ipykernel\comm\comm.py", line 66, in _publish_msg
    self.kernel.session.send(self.kernel.iopub_socket, msg_type,
AttributeError: 'NoneType' object has no attribute 'session'

I have found similar issue few years old, but I don't understand what is the solution to this. It is mentioning jupyter notebook. Do I have to use this package only inside jupyter?