Samples Python:

* Unused variables
* Bad identation

samples/python/digits_video.py

@@ -35,7 +35,7 @@ def main():
         model.load_(classifier_fn) #Known bug: https://github.com/opencv/opencv/issues/4969
 
     while True:
-        ret, frame = cap.read()
+        _ret, frame = cap.read()
         gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
 
 
@@ -59,12 +59,12 @@ def main():
             cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0))
 
             bin_roi = bin[y:,x:][:h,:w]
-            gray_roi = gray[y:,x:][:h,:w]
 
             m = bin_roi != 0
             if not 0.1 < m.mean() < 0.4:
                 continue
             '''
+            gray_roi = gray[y:,x:][:h,:w]
             v_in, v_out = gray_roi[m], gray_roi[~m]
             if v_out.std() > 10.0:
                 continue