title: Return Status while cap.isOpened() at command line
body: <p>I read an mp4 video with Python 3.6.5 and OpenCV 3.4.1 and do some (resource-heavy) calculations with every single frame.</p>
  
  <p>I have the total number for frames (<code>length</code>) and the current one (<code>count</code>) of course, so I'd like to give a progress update in my command line, but unfortunately it shows everything only after the whole process is finished.</p>
  
  <pre><code>while cap.isOpened():
      ret, frame = cap.read()
  
      if ret:
          # Calculation stuff
          ...
  
          # Print the current status
          print("Frame %s/%s" % (count, length))
  
          count = count + 1
  </code></pre>
  
  <p>Unfortunately it only prints ALL after the video file is completely processed.
  How can I print a "live" status of the current frame?</p>
  
  <p>I use MINGW64 (Windows) as my Console</p>