class Dog():

"""一次模拟小狗的简单尝试"""

def _init_(self,name,age):

"""初始化属性"""

self.name = name

self.age = age

def sit(self):

"""模拟小狗被命令时蹲下"""

print(self.name.title() + ' is now sitting.')

def roll_over(self):

"""模拟小狗被命令时打滚"""

print(self.name.title() + ' rolled over!')

my_dog = Dog('willie',6)

--snip--

print("My dog's name is " + my_dog.name.title() + ".")

print("My dog is " + str(my_dog.age) + " years old.")