Source code for axelrod.strategies.handshake

from typing import List

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

C, D = Action.C, Action.D

[docs]class Handshake(Player): """Starts with C, D. If the opponent plays the same way, cooperate forever, else defect forever. Names: - Handshake: [Robson1990]_ """ name = "Handshake" 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, initial_plays: List[Action] = None) -> None: super().__init__() if not initial_plays: initial_plays = [C, D] self.initial_plays = initial_plays
[docs] def strategy(self, opponent: Player) -> Action: # Begin by playing the sequence C, D index = len(self.history) if index < len(self.initial_plays): return self.initial_plays[index] # If our opponent played [C, D] on the first two moves, cooperate # forever. Otherwise defect forever. if opponent.history[0 : len(self.initial_plays)] == self.initial_plays: return C return D