运行python 时出现TypeError: obj() takes no parametrs

运行以下代码时出现TypeError: obj() takes no parametrs

root cause: init前后各有两个下划线"_", 但代码中只写了一个

class Dog():
   
    def _init_(self,name,age):
        self.name=name
        self.age=age

    def sit(self):
        print(self.name.title()+" is now siting.")

    def roll_over(self):
        print(self.name.title()+" rolled over!")


my_dog=Dog('haha',6)
print("my dog's name is "+my_dog.name.title()+".")
print("my dog is "+str(my_dog.age)+" years old")
my_dog.sit()
my_dog.roll_over()

正确代码应该是：

class Dog():
    """一次模拟小狗的简单测试"""
    def __init__(self,name,age):
        """初始化属性name and age"""
        self.name=name
        self.age=age

    def sit(self):
        """模拟小狗听到命令时蹲下"""
        print(self.name.title()+" is now siting.")

    def roll_over(self):
        """模拟小狗听到命令时打滚"""
        print(self.name.title()+" rolled over!")


my_dog=Dog('haha',6)
print("my dog's name is "+my_dog.name.title()+".")
print("my dog is "+str(my_dog.age)+" years old")
my_dog.sit()
my_dog.roll_over()