错误 AttributeError: 'NoneType' 对象没有属性 'kernel'

Question

有这个 javascript 代码可以在 colab 上运行您的本地系统摄像头，该 .ipynb 文件在 colab 上运行良好并且摄像头打开但是当我尝试将其转换为 .py 并在我的本地系统上运行它时会弹出此错误，我的系统中安装了其他 google-colab 库。

用于运行相机的js代码：

from IPython.display import display, Javascript
from google.colab.output import eval_js
from base64 import b64decode

def take_photo(filename='photo.jpg', quality=0.8):
  js = Javascript('''
    async function takePhoto(quality) {
      const div = document.createElement('div');
      const capture = document.createElement('button');
      capture.textContent = 'Capture';
      div.appendChild(capture);

      const video = document.createElement('video');
      video.style.display = 'block';
      const stream = await navigator.mediaDevices.getUserMedia({video: true});

      document.body.appendChild(div);
      div.appendChild(video);
      video.srcObject = stream;
      await video.play();

      // Resize the output to fit the video element.
      google.colab.output.setIframeHeight(document.documentElement.scrollHeight, true);

      // Wait for Capture to be clicked.
      await new Promise((resolve) => capture.onclick = resolve);

      const canvas = document.createElement('canvas');
      canvas.width = video.videoWidth;
      canvas.height = video.videoHeight;
      canvas.getContext('2d').drawImage(video, 0, 0);
      stream.getVideoTracks()[0].stop();
      div.remove();
      return canvas.toDataURL('image/jpeg', quality);
    }
    ''')
  display(js)
  data = eval_js('takePhoto({})'.format(quality))
  binary = b64decode(data.split(',')[1])
  with open(filename, 'wb') as f:
    f.write(binary)
  return filename

link to the js code

错误信息：

Traceback (most recent call last):
  File "repnet_task2.py", line 969, in <module>
    record_video(INTERVAL_IN_MS, int(RECORDING_TIME_IN_SECONDS*1000/INTERVAL_IN_MS)) 
  File "repnet_task2.py", line 752, in record_video
    eval_js('recordVideo({},{},{})'.format(interval_in_ms, num_frames, quality))
  File "/home/hp/Downloads/env/lib/python3.8/site-packages/google/colab/output/_js.py", line 35, in eval_js
    kernel = _ipython.get_kernel()
  File "/home/hp/Downloads/env/lib/python3.8/site-packages/google/colab/_ipython.py", line 28, in get_kernel
    return get_ipython().kernel
AttributeError: 'NoneType' object has no attribute 'kernel'