No need to use xrange for a short loop

fixes python3

Author: jenshnielsen

examples/pylab_examples/animation_demo.py

@@ -13,7 +13,7 @@
 y = np.arange(5)
 z = x * y[:, np.newaxis]
 
-for i in xrange(5):
+for i in range(5):
     if i == 0:
         p = plt.imshow(z)
         fig = plt.gcf()