Want to find contours -> ValueError: not enough values to unpack (expected 3, got 2), this appears

Question

My simple Python code is this

import cv2  img=cv2.imread('Materials/shapes.png')  blur=cv2.GaussianBlur(img,(3,3),0) gray=cv2.cvtColor(blur,cv2.COLOR_BGR2GRAY) returns,thresh=cv2.threshold(gray,80,255,cv2.THRESH_BINARY)  ret,contours,hierachy=cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)  for cnt in contours:      area=cv2.contourArea(cnt) #contour area          if (area>1220):         cv2.drawContours(img,[cnt],-1,(0,255,0),2)         cv2.imshow('RGB',img)         cv2.waitKey(1000)         print(len(cnt))  import numpy as np  contours=np.array(contours)  print(contours) 

This worked fine. But recently without me even making any changes. This was throwed to me

ret,contours,hierachy=cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)

ValueError: not enough values to unpack (expected 3, got 2)

Answer 1

the function cv2.findContours() has been changed to return only the contours and the hierarchy and not ret

you should change it to:

contours,hierachy=cv2.findContours(thresh,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)