Fix random differences between python 2 and 3

axelrod/moran.py

@@ -7,6 +7,7 @@
 from .deterministic_cache import DeterministicCache
 from .match import Match
 from .player import Player
+from .random_ import randrange
 
 
 def fitness_proportionate_selection(scores):
@@ -58,7 +59,7 @@ def __next__(self):
         # Fitness proportionate selection
         j = fitness_proportionate_selection(scores)
         # Randomly remove a strategy
-        i = random.randrange(0, len(self.players))
+        i = randrange(0, len(self.players))
         # Replace player i with clone of player j
         self.players[i] = self.players[j].clone()
         self.populations.append(self.population_distribution())

axelrod/random_.py

@@ -12,3 +12,9 @@ def random_choice(p=0.5):
     if r < p:
         return Actions.C
     return Actions.D
+
+def randrange(a, b):
+    """Python 2 / 3 compatible randrange."""
+    c = b - a
+    r = c * random.random()
+    return a + int(r)