CoopSim - A Computer Simulation of the Evolution of Cooperation. User's Manual
7.2.2 The Strategy class
Any strategy in the game must be derived from class Strategies.Strategy.
This class defines the two methods firstMove(self) and nextMove(self,
myMoves, opMoves). Both methods must return either 0 or 1, where 0
means “defection” and 1 stands for “cooperation”.
firstMove does not take any parameters except “self”, while
nextMove gets the list of its own moves during the previous rounds
of the current match as well as a list of its opponents previous moves.
Both lists are list of zeros and ones. Implementing your own user strategies
is pretty easy now: Simply derive a class from class Strategies.Strategy
and define the methods firstMove and nextMove, nothing else is needed,
neither a constructor, nor is it necessary to worry about a name for
the strategy, because the class name is automatically used as the strategies'
name. All state saving variables of your class must be reset in method
firstmove! This is necessary, because the same strategy object
is used in all matches of the tournament. Here is a simple example
of a custom strategy class:
"""Retailiate only when not having retailiated in
the last round already.
return 1 # start friendly
def nextMove(self, myMoves, opMoves):
if opMoves[-1] == 0 and myMoves[-1] != 0:
return 0 # retailiate
return 1 # cooperate
# Do not forget to instantiate your class, otherwise
# it will not appear among the available strategies!
lesser_tft = LesserTFT()