int参数必须是字符串，类似字节的对象或数字，而不是NoneType

Question

为什么会出现以下错误：

  

int（）参数必须是字符串，类似字节的对象或数字，而不是“ NoneType”

我认为我需要帮助弄清楚如何将无类型变量转换为字符串或整数，您可以通过以下代码帮助我解决问题吗？

fi = open("model.ckpt-45778","w")

for x in sorted(os.listdir("images")):
# Acquire frame and expand frame dimensions to have shape: [1, None,None, 3]
# i.e. a single-column array, where each item in the column has the pixel RGB value
    print(os.path.join("images", x))

    frame = cv2.imread(os.path.join("images", x))
    frame_expanded = np.expand_dims(frame, axis=0)
#print(frame)
# Perform the actual detection by running the model with the image as input
    (boxes, scores, classes, num) = sess.run(
        [detection_boxes, detection_scores, detection_classes,num_detections],
        feed_dict={image_tensor: frame_expanded})

    print(len(scores[0]))
    print(scores)
    print(len(classes[0]))
    print(classes)
    maxv = {}
    for i in range(1, NUM_CLASSES+1):
      maxv[i]=0
    for i in range(0, len(scores[0])):
      maxv[classes[0][i]]=max(maxv[classes[0][i]],scores[0][i])
    print(maxv)
    for i in range(1, NUM_CLASSES+1):
      fi.write(str(maxv[i])+"\t")
    fi.write("\n")
# Draw the results of the detection (aka 'visulaize the results')
    vis_util.visualize_boxes_and_labels_on_image_array( 
        frame,
        np.squeeze(boxes),
        np.squeeze(classes).astype(np.int32),
        np.squeeze(scores),
        category_index,
        use_normalized_coordinates=True,
        line_thickness=8,
        min_score_thresh=0.60)
    cv2.imwrite(os.path.join("test_timeline", x), frame)

#print(frame)
# All the results have been drawn on the frame, so it's time to display it.
    cv2.imshow('Object detector', frame)
    cv2.imwrite('Salida/' + str(x), frame)
# Press 'q' to quit
    if cv2.waitKey(1) == ord('q'):
            break
# Clean up
#video.release()
cv2.destroyAllWindows()

    images\test
    Traceback (most recent call last):
      File "C:\Tensor\models\research\object_detection\Webcam0.py", line 88, in 
        feed_dict={image_tensor: frame_expanded})
      File "C:\Users\Tg\Anaconda3\envs\Tensor\lib\site-packages\tensorflow\python\client\session.py",
line 950, in run
        run_metadata_ptr)
      File "C:\Users\Tg\Anaconda3\envs\Tensor\lib\site-packages\tensorflow\python\client\session.py",
line 1142, in _run
        np_val = np.asarray(subfeed_val, dtype=subfeed_dtype)
      File "C:\Users\Tg\Anaconda3\envs\Tensor\lib\site-packages\numpy\core\numeric.py",
line 538, in asarray
        return array(a, dtype, copy=False, order=order)
    TypeError: int() argument must be a string, a bytes-like object or a number, not 'NoneType'