Error resolution

Error reproduction

Traceback (most recent call last):
  File "D:/pythonProjects/Object_movement/object_movement.py", line 88, in <module>
    c = max(cnts, key=cv2.contourArea)
cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-i1s8y2i1\opencv\modules\imgproc\src\shapedescr.cpp:315: error: (-215:Assertion failed) npoints >= 0 && (depth == CV_32F || depth == CV_32S) in function 'cv::contourArea'

source code

cnts = cv2.findContours(mask.copy(), cv2.RETR_EXTERNAL,
                            cv2.CHAIN_APPROX_SIMPLE)
cnts=cnts[1]

Modified code

cnts, hierarchy = cv2.findContours(mask.copy(), cv2.RETR_EXTERNAL,
                                       cv2.CHAIN_APPROX_SIMPLE)

Error reporting reason

New CV2 Findcontours returns two values. The result of [0] is contour instead of [1]