class Dog():
"""this class initialize a class of a dog"""
def init(self,name,age,master='Rose'):
    self.name = name
    self.a = age
    self.m = master
    self.typee = 'animal'
       def sit(self):
       print(self.name + " is sitting.")
       def roll_over(self):
       print(self.name + " rolled over.")
       def master(self):
       print(self.name + " 's master is " + self.m)
       def type(self):
        print(self.name + " 's type is " + self.typee + ".")
       def age(self):
         print(self.name + " 's age is " + self.a)
       def met(self):
         print("This is a test!!!")

   dog1=Dog("宝贝")
   dog1.sit()
   dog1.roll_over()
   dog1.master()
   dog1.type()
   dog1.age()
   dog1.met()
错误类型：
C:\Users\Administrator\PycharmProjects\pythonProject\venv\Scripts\python.exe C:/Users/Administrator/PycharmProjects/pythonProject/突然.py
Traceback (most recent call last):
File "C:\Users\Administrator\PycharmProjects\pythonProject\突然.py", line 21, in <module>
dog1=Dog("宝贝")
TypeError: init() missing 1 required positional argument: 'age'

Process finished with exit code 1