Source code for axelrod.strategies.punisher

from typing import List

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

C, D = Action.C, Action.D


[docs]class Punisher(Player): """ A player starts by cooperating however will defect if at any point the opponent has defected, but forgets after meme_length matches, with 1<=mem_length<=20 proportional to the amount of time the opponent has played D, punishing that player for playing D too often. Names: - Punisher: Original name by Geraint Palmer """ name = "Punisher" classifier = { "memory_depth": float("inf"), # Long memory "stochastic": False, "makes_use_of": set(), "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, } def __init__(self) -> None: """ Initialised the player """ super().__init__() self.mem_length = 1 self.grudged = False self.grudge_memory = 1
[docs] def strategy(self, opponent: Player) -> Action: """ Begins by playing C, then plays D for an amount of rounds proportional to the opponents historical '%' of playing D if the opponent ever plays D """ if self.grudge_memory >= self.mem_length: self.grudge_memory = 0 self.grudged = False if self.grudged: self.grudge_memory += 1 return D elif D in opponent.history[-1:]: self.mem_length = (opponent.defections * 20) // len(opponent.history) self.grudged = True return D return C
[docs]class InversePunisher(Player): """ An inverted version of Punisher. The player starts by cooperating however will defect if at any point the opponent has defected, and forgets after mem_length matches, with 1 <= mem_length <= 20. This time mem_length is proportional to the amount of time the opponent has played C. Names: - Inverse Punisher: Original name by Geraint Palmer """ name = "Inverse Punisher" classifier = { "memory_depth": float("inf"), # Long memory "stochastic": False, "makes_use_of": set(), "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, } def __init__(self) -> None: super().__init__() self.history = [] # type: List[Action] self.mem_length = 1 self.grudged = False self.grudge_memory = 1
[docs] def strategy(self, opponent: Player) -> Action: """ Begins by playing C, then plays D for an amount of rounds proportional to the opponents historical '%' of playing C if the opponent ever plays D. """ if self.grudge_memory >= self.mem_length: self.grudge_memory = 0 self.grudged = False if self.grudged: self.grudge_memory += 1 return D elif D in opponent.history[-1:]: self.mem_length = (opponent.cooperations * 20) // len(opponent.history) if self.mem_length == 0: self.mem_length += 1 self.grudged = True return D return C
[docs]class LevelPunisher(Player): """ A player starts by cooperating however, after 10 rounds will defect if at any point the number of defections by an opponent is greater than 20%. Names: - Level Punisher: [Eckhart2015]_ """ name = "Level Punisher" classifier = { "memory_depth": float("inf"), # Long Memory "stochastic": False, "makes_use_of": set(), "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, }
[docs] def strategy(self, opponent: Player) -> Action: if len(opponent.history) < 10: return C elif (len(opponent.history) - opponent.cooperations) / len( opponent.history ) > 0.2: return D else: return C
[docs]class TrickyLevelPunisher(Player): """ A player starts by cooperating however, after 10, 50 and 100 rounds will defect if at any point the percentage of defections by an opponent is greater than 20%, 10% and 5% respectively. Names: - Tricky Level Punisher: [Eckhart2015]_ """ name = "Tricky Level Punisher" classifier = { "memory_depth": float("inf"), # Long Memory "stochastic": False, "makes_use_of": set(), "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, }
[docs] def strategy(self, opponent: Player) -> Action: if len(opponent.history) == 0: return C if len(opponent.history) < 10: if opponent.defections / len(opponent.history) > 0.2: return D if len(opponent.history) < 50: if opponent.defections / len(opponent.history) > 0.1: return D if len(opponent.history) < 100: if opponent.defections / len(opponent.history) > 0.05: return D return C