Changing the input be any iterable for transformer.

- Removing a redundant import?
- Adding nicer docstring.

Author: drvinceknight

axelrod/strategy_transformers.py

@@ -8,7 +8,7 @@
 
 import inspect
 import random
-from types import FunctionType
+import collections
 from numpy.random import choice
 
 from .actions import Actions, flip_action
@@ -246,6 +246,16 @@ def mixed_wrapper(player, opponent, action, probability, m_player):
     of players or a single player.
 
     In essence creating a mixed strategy.
+
+    Parameters
+    ----------
+
+    probability: a float (or integer: 0 or 1) OR an iterable representing a
+        an incomplete probability distribution (entries to do not have to sum to
+        1). Eg: 0, 1, [.5,.5], (.5,.3)
+    m_players: a single player class or iterable representing set of player
+        classes to mix from.
+        Eg: axelrod.TitForTat, [axelod.Cooperator, axelrod.Defector]
     """
 
     # If a single probability, player is passed
@@ -254,14 +264,15 @@ def mixed_wrapper(player, opponent, action, probability, m_player):
         probability = [probability]
 
     # If a probability distribution, players is passed
-    if isinstance(probability, list) and isinstance(m_player, list):
+    if isinstance(probability, collections.Iterable) and \
+            isinstance(m_player, collections.Iterable):
         mutate_prob = sum(probability)  # Prob of mutation
         if mutate_prob > 0:
             # Distribution of choice of mutation:
             normalised_prob = [prob / float(mutate_prob)
                                for prob in probability]
             if random.random() < mutate_prob:
-                p = choice(m_player, p=normalised_prob)()
+                p = choice(list(m_player), p=normalised_prob)()
                 p.history = player.history
                 return p.strategy(opponent)
 

axelrod/tests/unit/test_strategy_transformers.py

@@ -212,7 +212,7 @@ def test_apology(self):
             p1.play(p2)
         self.assertEqual(p1.history, [D, D, C, D, D, C])
 
-    def test_mutate(self):
+    def test_mixed(self):
         """Tests the MixedTransformer."""
         probability = 1
         MD = MixedTransformer(probability, axelrod.Cooperator)(axelrod.Defector)
@@ -248,7 +248,7 @@ def test_mutate(self):
         self.assertEqual(p1.history, [C, C, C, C, C])
 
         # Decorate a cooperator putting all weight on Defector
-        probability = [0, 0, 1]
+        probability = (0, 0, 1)  # Note can also pass tuple
         strategies = [axelrod.TitForTat, axelrod.Grudger, axelrod.Defector]
         MD = MixedTransformer(probability, strategies)(axelrod.Cooperator)