单步调试的时候 update()已经被调用了,运行到if判断语句,就直接跳过print()语句,直接到notifyObservers()函数里面了,不知道为什么?
from abc import ABCMeta,abstractmethod
class Observer(metaclass=ABCMeta): #抽象观察者
'观察者的基类'
@abstractmethod
def update(self,observable,object):
pass
class WashingMode(Observer):
'该模式用于洗澡'
def update(self,waterHeater,object):
if isinstance(Observable,WaterHeater) and Observable.getTemperature() >= 50 and Observable.getTemperature() < 70 :
print("水已烧好!温度正好,可以用来洗澡了。") #此行显示不了
class DrinkingMode(Observer):
'该模式用于饮用'
def update(self,waterHeater,object):
if isinstance(Observable,WaterHeater) and Observable.getTemperature() >= 100:
print("水已烧开!可以用来饮用了。") #此行显示不了
class Observable: #被观察者
'被观察者的基类'
def __init__(self):
self.__observers=[]
def addObserver(self,observer):
self.__observers.append(observer)
def removeObserver(self,observer):
self.__observers.remove(observer)
def notifyObservers(self,object=0):
for o in self.__observers:
o.update(self,object)
class WaterHeater(Observable):
'热水器:战胜寒冬的有力武器'
def __init__(self):
super().__init__()
self.__temperature=25
def getTemperature(self):
return self.__temperature
def setTemperature(self,temperature):
self.__temperature=temperature
print('当前温度是: ' + str(self.__temperature) + 'C')
self.notifyObservers()
def testWaterHeater():
heater=WaterHeater()
washingObser=WashingMode()
drinkingObser=DrinkingMode()
heater.addObserver(washingObser)
heater.addObserver(drinkingObser)
heater.setTemperature(40)
heater.setTemperature(60)
heater.setTemperature(100)
testWaterHeater()