robertj

#!/usr/bin/env pythonclass RegisterableParent:    def __init__(self):        self._updates = []         self.value = 0    def calculate(self):        self._set(self.formula())    def _set(self, val):        self.value = val        for stat in self._updates:            stat.calculate()    def get(self):        return self.valueclass PrimitiveStat(RegisterableParent):    def __init__(self):        RegisterableParent.__init__(self)        self.set = self._setclass CompoundStat(RegisterableParent):    def __init__(self, base=PrimitiveStat()):        RegisterableParent.__init__(self)        self.multipliers = MultiplyingCollection()        self.bonuses = AddingCollection()        self.base = base         for stat in [self.multipliers, self.bonuses, self.base]:            stat._updates.append(self)    def formula(self):        return (self.multipliers.value  * self.base.value) + self.bonuses.valueclass CalculatedStat(RegisterableParent):     def __init__(self, **kwargs):        RegisterableParent.__init__(self)        self._toolbox = {}        for arg in kwargs:            self._toolbox[arg] = kwargs[arg]         for stat in self._toolbox:            self._toolbox[stat]._updates.append(self)    def getStat(self, stat):        return self._toolbox[stat].valueclass Bonus:    def __init__(self, value):        self.value = value        self._updates = [] class BonusCollectionParent(RegisterableParent):    def __init__(self):        RegisterableParent.__init__(self)        self.bonuses = set()    def register(self, item):        self.bonuses.add(item)        self.calculate()    def unregister(self, item):        self.bonuses.remove(item)        self.calculate()class AddingCollection(BonusCollectionParent):    def formula(self):        x = 0        for bonus in self.bonuses:            x += bonus.value        return xclass MultiplyingCollection(BonusCollectionParent):    def formula(self):        x = 1         for bonus in self.bonuses:            x *= (1 + bonus)        return xlevel = PrimitiveStat()strength = CompoundStat()strength.base.set(13)bonus_attack_power = PrimitiveStat()bonus_attack_power.set(5)attack_power = CalculatedStat(level=level, strength=strength, bonus_attack_power = bonus_attack_power)attack_power.formula = lambda: attack_power.getStat('level') + attack_power.getStat('strength') * 2 + attack_power.getStat('bonus_attack_power')hp = CalculatedStat(level=level)hp.formula = lambda: hp.getStat('level') * 10level.set(4)print level.valueprint hp.valueprint attack_power.valuelevel.set(level.value + 1)print attack_power.valuebonus_attack_power.set(0)print attack_power.valuetest = AddingCollection()g = Bonus(3)test.register(g)print test.valuetest.register(Bonus(4))print test.valuetest.unregister(g)print test.value