In Python/OpenCV 4.4.0, findContours returns only 2 values, you list 3.
You show:
image,contours,hierarchy = cv2.findContours(binary,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)
OpenCV 4.4.0, lists:
contours, hierarchy = cv.findContours(image, mode, method[, contours[, hierarchy[, offset]]])
Please always check the documentation. See
https://docs.opencv.org/4.4.0/d3/dc0/group__imgproc__shape.html#gadf1ad6a0b82947fa1fe3c3d497f260e0
One way to handle this in a version independent way, if all you want are the contours, is (credit to @nathancy):
contours = cv2.findContours(binary, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
contours = contours[0] if len(contours) == 2 else contours[1]
If you do not want all nested contours, then use RETR_EXTERNAL and not RETR_LIST.