Source code for axelrod.strategies.verybad

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

C, D = Action.C, Action.D

[docs]class VeryBad(Player): """ It cooperates in the first three rounds, and uses probability (it implements a memory, which stores the opponent’s moves) to decide for cooperating or defecting. Due to a lack of information as to what that probability refers to in this context, probability(P(X)) refers to (Count(X)/Total_Moves) in this implementation P(C) = Cooperations / Total_Moves P(D) = Defections / Total_Moves = 1 - P(C) Names: - VeryBad: [Andre2013]_ """ name = "VeryBad" classifier = { "memory_depth": float("inf"), "stochastic": False, "makes_use_of": set(), "long_run_time": False, "inspects_source": False, "manipulates_source": False, "manipulates_state": False, }
[docs] @staticmethod def strategy(opponent: Player) -> Action: total_moves = len(opponent.history) if total_moves < 3: return C cooperations = opponent.cooperations cooperation_probability = cooperations / total_moves if cooperation_probability > 0.5: return C elif cooperation_probability < 0.5: return D else: return opponent.history[-1]