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,
"long_run_time": False,
"inspects_source": False,
"manipulates_source": False,
"manipulates_state": False,
}
[docs] @staticmethod
def strategy(opponent: Player) -> Action:
"""Actual strategy definition that determines player's 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]