与孩子一起学编程14章
这一章，开始学习对象
什么是对象，如何创建和使用对象。对象包括两个方面：属性和方法。
如果要建立一个球，球就是一个对象，他要有属性和方法。
class HotDog: def __init__(self): self.cooked_level = 0 self.cooked_string = "Raw" self.condiments = [] def __str__(self): msg = "hot dog" if len(self.condiments) > 0: msg = msg + " with" for i in self.condiments: msg = msg + i + ", " msg = msg.strip(", ") msg = self.cooked_string + " " + msg + "." return msg def cook(self, time): self.cooked_level = self.cooked_level + time if self.cooked_level > 8: self.cooked_string = "Charcoal" elif self.cooked_level > 5: self.cooked_string = "Well-done" elif self.cooked_level > 3: self.cooked_string = "Medium" else: self.cooked_string = "Raw" def addCondiment(self, condiment): self.condiments.append(condiment) myDog = HotDog()print myDogprint "Cooking hot dog for 4 minutes..."myDog.cook(4)print myDogprint "Cooking hot dog for 3 more minutes..."myDog.cook(3)print myDogprint "What happens if I cook it for 10 more minutes?"myDog.cook(10)print myDogprint "Now, I'm going to add some stuff on my hot dog"myDog.addCondiment("ketchup")myDog.addCondiment("mustard")print myDog