title: ValueError: too many values to unpack (expected 2) cv2
body: <p>Hi all i having facing the above error while executing the code below.</p>
  
  <pre><code>img = cv2.imread('034.jpg',0)
  
  ret,thresh = cv2.threshold(img,127,255,0)
  
  contours,hierarchy = cv2.findContours(thresh, 1, 2)
  </code></pre>
  
  <p>error as:</p>
  
  <blockquote>
    <p>File "bb.py", line 6, in 
        contours,hierarchy = cv2.findContours(thresh, 1, 2) ValueError: too many values to unpack (expected 2)</p>
  </blockquote>