Avoid division by zero

Author: idanpa

wpm/game.py

@@ -125,12 +125,16 @@ def wpm(self, elapsed):
         """Words per minute."""
         if self.start is None:
             return 0
+        if not elapsed:
+            return 0
         return min((60.0 * self.position / 5.0) / elapsed, 999)
 
     def cps(self, elapsed):
         """Characters per second."""
         if self.start is None:
             return 0
+        if not elapsed:
+            return 0
         return min(float(self.position) / elapsed, 99)
 
     @property