Drop Python2 support.

samples/python/camshift.py

@@ -22,14 +22,6 @@ Keys:
     b     - toggle back-projected probability visualization
 '''
 
-# Python 2/3 compatibility
-from __future__ import print_function
-import sys
-PY3 = sys.version_info[0] == 3
-
-if PY3:
-    xrange = range
-
 import numpy as np
 import cv2 as cv
 
@@ -68,7 +60,7 @@ class App(object):
         bin_count = self.hist.shape[0]
         bin_w = 24
         img = np.zeros((256, bin_count*bin_w, 3), np.uint8)
-        for i in xrange(bin_count):
+        for i in range(bin_count):
             h = int(self.hist[i])
             cv.rectangle(img, (i*bin_w+2, 255), ((i+1)*bin_w-2, 255-h), (int(180.0*i/bin_count), 255, 255), -1)
         img = cv.cvtColor(img, cv.COLOR_HSV2BGR)