Update pyplot_formatstr.py

Author: Aseem Bansal

doc/pyplots/pyplot_formatstr.py

@@ -1,5 +1,4 @@
 import matplotlib.pyplot as plt
 plt.plot([1,2,3,4], [1,4,9,16], 'ro')
 plt.axis([0, 6, 0, 20])
-
-
+plt.show()