Source code for axelrod.strategies.worse_and_worse

from axelrod.action import Action
from axelrod.player import Player

C, D = Action.C, Action.D


[docs]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, "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, }
[docs] def strategy(self, opponent: Player) -> Action: current_round = len(self.history) + 1 probability = 1 - current_round / 1000 return self._random.random_choice(probability)
[docs]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, "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, }
[docs] def strategy(self, opponent: Player) -> Action: current_round = len(self.history) + 1 expected_length = self.match_attributes["length"] probability = 1 - current_round / expected_length return self._random.random_choice(probability)
[docs]class WorseAndWorse2(Player): """ Plays as tit for tat during the first 20 moves. Then defects with probability (current turn - 20) / current turn. Therefore it is more and more likely to defect as the round goes on. Names: - Worse and Worse 2: [Prison1998]_ """ name = "Worse and Worse 2" classifier = { "memory_depth": float("inf"), "stochastic": True, "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, }
[docs] def strategy(self, opponent: Player) -> Action: current_round = len(self.history) + 1 if current_round == 1: return C elif current_round <= 20: return opponent.history[-1] else: probability = 20 / current_round return self._random.random_choice(probability)
[docs]class WorseAndWorse3(Player): """ Cooperates in the first turn. Then defects with probability no. of opponent defects / (current turn - 1). Therefore it is more likely to defect when the opponent defects for a larger proportion of the turns. Names: - Worse and Worse 3: [Prison1998]_ """ name = "Worse and Worse 3" classifier = { "memory_depth": float("inf"), "stochastic": True, "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, }
[docs] def strategy(self, opponent: Player) -> Action: current_round = len(self.history) + 1 if current_round == 1: return C else: probability = 1 - opponent.defections / (current_round - 1) return self._random.random_choice(probability)