Added Average_Copier strategy (no tests sorry)

.gitignore

@@ -1 +1,2 @@
 *pyc
+*.DS_Store

axelrod/strategies/__init__.py

@@ -5,6 +5,7 @@
 from titfortat import *
 from gobymajority import *
 from alternator import *
+from averagecopier import *
 
 
 strategies = [
@@ -15,4 +16,5 @@
         GoByMajority,
         Random,
         Alternator,
+        AverageCopier,
         ]

axelrod/strategies/averagecopier.py

@@ -0,0 +1,24 @@
+from axelrod import Player
+import random
+
+class AverageCopier(Player):
+    """
+    The player will cooperate with probability p if the opponent's cooperation ratio is p
+    """
+    def strategy(self, opponent):
+        """
+        Randomly picks a strategy (not affected by history)
+        """
+        if len(opponent.history) == 0:
+            return random.choice(['C', 'D'])
+        p = sum([s == 'C' for s in opponent.history]) / len(opponent.history)
+        rnd_num = random.random()
+        if rnd_num < p:
+            return 'C'
+        return 'D'
+
+    def __repr__(self):
+        """
+        The string method for the strategy:
+        """
+        return 'Average Copier'

axelrod/tests/test_averagecopier.py

@@ -0,0 +1,54 @@
+"""
+Test for the average_copier strategy
+"""
+import unittest
+import axelrod
+import random
+
+class TestAverageCopier(unittest.TestCase):
+
+    def test_initial_strategy(self):
+        """
+        Test that the first strategy is picked randomly
+        """
+        random.seed(1)
+        P1 = axelrod.AverageCopier()
+        P2 = axelrod.Player()
+        self.assertEqual(P1.strategy(P2), 'C')
+        self.assertEqual(P1.strategy(P2), 'D')
+        self.assertEqual(P1.strategy(P2), 'D')
+        self.assertEqual(P1.strategy(P2), 'C')
+        self.assertEqual(P1.strategy(P2), 'C')
+        self.assertEqual(P1.strategy(P2), 'C')
+        self.assertEqual(P1.strategy(P2), 'D')
+        self.assertEqual(P1.strategy(P2), 'D')
+        self.assertEqual(P1.strategy(P2), 'C')
+        self.assertEqual(P1.strategy(P2), 'C')
+
+    def test_when_oppenent_all_Cs(self):
+        """
+        Tests that if opponent has played all C then player chooses C
+        """
+        random.seed(5)
+        P1 = axelrod.AverageCopier()
+        P2 = axelrod.Player()
+        P2.history = ['C', 'C', 'C', 'C']
+        self.assertEqual(P1.strategy(P2), 'C')
+        self.assertEqual(P1.strategy(P2), 'C')
+        self.assertEqual(P1.strategy(P2), 'C')
+
+    def test_when_opponent_all_Ds(self):
+        """
+        Tests that if opponent has played all D then player chooses D
+        """
+        random.seed(5)
+        P1 = axelrod.AverageCopier()
+        P2 = axelrod.Player()
+        P2.history = ['D', 'D', 'D', 'D']
+        self.assertEqual(P1.strategy(P2), 'D')
+        self.assertEqual(P1.strategy(P2), 'D')
+        self.assertEqual(P1.strategy(P2), 'D')
+
+    def test_representation(self):
+        P1 = axelrod.AverageCopier()
+        self.assertEqual(str(P1), 'Average Copier')