Modernize Python 2 code to get ready for Python 3

dynamic_programming/edit_distance.py

@@ -51,11 +51,10 @@ class EditDistance:
         return self.__solveDP(len(A)-1, len(B)-1)
 
 if __name__ == '__main__':
-        import sys
-        if sys.version_info.major < 3:
-            input_function = raw_input
-        else:
-            input_function = input
+        try:
+            raw_input          # Python 2
+        except NameError:
+            raw_input = input  # Python 3
 
         solver = EditDistance()
 
@@ -63,10 +62,10 @@ if __name__ == '__main__':
         print()
 
         print("Enter the first string: ", end="")
-        S1 = input_function()
+        S1 = raw_input().strip()
 
         print("Enter the second string: ", end="")
-        S2 = input_function()
+        S2 = raw_input().strip()
 
         print()
         print("The minimum Edit Distance is: %d" % (solver.solve(S1, S2)))