Merge pull request #724 from Huaraz2/WorseAndWorse

New Strategy From the PRISON (http://www.lifl.fr/IPD/ipd.frame.html)

Author: meatballs

axelrod/strategies/_strategies.py

@@ -59,7 +59,7 @@
     TitForTat, TitFor2Tats, TwoTitsForTat, Bully, SneakyTitForTat,
     SuspiciousTitForTat, AntiTitForTat, HardTitForTat, HardTitFor2Tats,
     OmegaTFT, Gradual, ContriteTitForTat, SlowTitForTwoTats, AdaptiveTitForTat)
-
+from .worse_and_worse import (WorseAndWorse, KnowledgeableWorseAndWorse)
 
 # Note: Meta* strategies are handled in .__init__.py
 
@@ -141,6 +141,7 @@
     Inverse,
     InversePunisher,
     Joss,
+    KnowledgeableWorseAndWorse,
     LimitedRetaliate,
     LimitedRetaliate2,
     LimitedRetaliate3,
@@ -195,12 +196,13 @@
     Willing,
     WinShiftLoseStay,
     WinStayLoseShift,
+    WorseAndWorse,
     ZDExtort2,
     ZDExtort2v2,
     ZDExtort4,
     ZDGTFT2,
     ZDGen2,
     ZDSet2,
     e,
-    
+
 ]

axelrod/strategies/worse_and_worse.py

@@ -0,0 +1,59 @@
+from axelrod import Actions, Player, random_choice
+
+C, D = Actions.C, Actions.D
+
+class WorseAndWorse (Player):
+    """
+    Defects with probability of 'current turn / 1000'. Therefore
+    it is more and more likely to defect as the round goes on.
+
+    Source code available at the download tab of [PRISON1998]_
+
+
+    Names:
+        - Worse and Worse: [PRISON1998]_
+
+    """
+
+    name = 'Worse and Worse'
+    classifier = {
+        'memory_depth': float('inf'),
+        'stochastic': True,
+        'makes_use_of': set(),
+        'long_run_time': False,
+        'inspects_source': False,
+        'manipulates_source': False,
+        'manipulates_state': False
+    }
+
+    def strategy(self, opponent):
+        current_round = len(self.history) + 1
+        probability = 1 - float(current_round) / 1000
+        return random_choice(probability)
+
+
+class KnowledgeableWorseAndWorse (Player):
+    """
+    This strategy is based on 'Worse And Worse' but will defect with probability
+    of 'current turn / total no. of turns'.
+
+    Names:
+        - Knowledgeable Worse and Worse: Original name by Adam Pohl
+    """
+
+    name = 'Knowledgeable Worse and Worse'
+    classifier = {
+        'memory_depth': float('inf'),
+        'stochastic': True,
+        'makes_use_of': set(['length']),
+        'long_run_time': False,
+        'inspects_source': False,
+        'manipulates_source': False,
+        'manipulates_state': False
+    }
+
+    def strategy(self, opponent):
+        current_round = len(self.history) + 1
+        expected_length = self.match_attributes['length']
+        probability = 1 - float(current_round) / expected_length
+        return random_choice(probability)

axelrod/tests/unit/test_player.py

@@ -1,5 +1,4 @@
 # -*- coding: utf-8 -*-
-import copy
 import inspect
 import random
 import unittest
@@ -89,7 +88,7 @@ def test_responses(test_class, P1, P2, history_1, history_2, responses,
     """
 
     if random_seed:
-        random.seed(random_seed)
+        axelrod.seed(random_seed)
     # Force the histories, In case either history is impossible or if some
     # internal state needs to be set, actually submit to moves to the strategy
     # method. Still need to append history manually.

axelrod/tests/unit/test_worse_and_worse.py

@@ -0,0 +1,107 @@
+"""Test for the Worse and Worse strategies."""
+
+import axelrod
+
+from .test_player import TestPlayer
+
+C, D = axelrod.Actions.C, axelrod.Actions.D
+
+class TestWorseAndWorse(TestPlayer):
+
+    name = "Worse and Worse"
+    player = axelrod.WorseAndWorse
+    expected_classifier = {
+        'memory_depth': float('inf'),
+        'stochastic': True,
+        'makes_use_of': set(),
+        'long_run_time': False,
+        'inspects_source': False,
+        'manipulates_source': False,
+        'manipulates_state': False
+    }
+
+    def test_strategy(self):
+        """
+        Test that the strategy gives expected behaviour
+        """
+
+        axelrod.seed(8)
+        opponent = axelrod.Cooperator()
+        player = axelrod.WorseAndWorse()
+        match = axelrod.Match((opponent, player), turns=10)
+        self.assertEqual(match.play(), [('C', 'C'),
+                                        ('C', 'C'),
+                                        ('C', 'C'),
+                                        ('C', 'C'),
+                                        ('C', 'C'),
+                                        ('C', 'C'),
+                                        ('C', 'D'),
+                                        ('C', 'C'),
+                                        ('C', 'C'),
+                                        ('C', 'C')])
+
+        # Test that behaviour does not depend on opponent
+        opponent = axelrod.Defector()
+        player = axelrod.WorseAndWorse()
+        axelrod.seed(8)
+        match = axelrod.Match((opponent, player), turns=10)
+        self.assertEqual(match.play(), [('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'D'),
+                                        ('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C')])
+
+
+class TestWorseAndWorseRandom(TestPlayer):
+
+    name = "Knowledgeable Worse and Worse"
+    player = axelrod.KnowledgeableWorseAndWorse
+    expected_classifier = {
+        'memory_depth': float('inf'),
+        'stochastic': True,
+        'makes_use_of': set(['length']),
+        'long_run_time': False,
+        'inspects_source': False,
+        'manipulates_source': False,
+        'manipulates_state': False
+    }
+
+    def test_strategy(self):
+        """
+        Test that the strategy gives expected behaviour
+        """
+        axelrod.seed(1)
+        opponent = axelrod.Cooperator()
+        player = axelrod.KnowledgeableWorseAndWorse()
+        match = axelrod.Match((opponent, player), turns=5)
+        self.assertEqual(match.play(), [('C', 'C'),
+                                        ('C', 'D'),
+                                        ('C', 'D'),
+                                        ('C', 'D'),
+                                        ('C', 'D')])
+
+        # Test that behaviour does not depend on opponent
+        opponent = axelrod.Defector()
+        player = axelrod.KnowledgeableWorseAndWorse()
+        axelrod.seed(1)
+        match = axelrod.Match((opponent, player), turns=5)
+        self.assertEqual(match.play(), [('D', 'C'),
+                                        ('D', 'D'),
+                                        ('D', 'D'),
+                                        ('D', 'D'),
+                                        ('D', 'D')])
+
+        # Test that behaviour changes when does not know length.
+        axelrod.seed(1)
+        match = axelrod.Match((opponent, player), turns=5,
+                              match_attributes={'length': float('inf')})
+        self.assertEqual(match.play(), [('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C'),
+                                        ('D', 'C')])

docs/reference/all_strategies.rst

@@ -60,6 +60,9 @@ Here are the docstrings of all the strategies in the library.
 .. automodule:: axelrod.strategies.gobymajority
    :members:
    :undoc-members:
+.. automodule:: axelrod.strategies.gradualkiller
+   :members:
+   :undoc-members:
 .. automodule:: axelrod.strategies.grudger
    :members:
    :undoc-members:
@@ -120,6 +123,6 @@ Here are the docstrings of all the strategies in the library.
 .. automodule:: axelrod.strategies.titfortat
    :members:
    :undoc-members:
-.. automodule:: axelrod.strategies.gradualkiller
+.. automodule:: axelrod.strategies.worse_and_worse
    :members:
-   :undoc-members:
+   :undoc-members:

docs/tutorials/advanced/classification_of_strategies.rst

@@ -47,7 +47,7 @@ strategies::
     ... }
     >>> strategies = axl.filtered_strategies(filterset)
     >>> len(strategies)
-    35
+    37
 
 
 Or, to find out how many strategies only use 1 turn worth of memory to
@@ -81,7 +81,7 @@ length of each match of the tournament::
     ... }
     >>> strategies = axl.filtered_strategies(filterset)
     >>> len(strategies)
-    4
+    5
 
 Note that in the filterset dictionary, the value for the 'makes_use_of' key
 must be a list. Here is how we might identify the number of strategies that use