python创建类和类方法

python创建类和类方法

创建一个类的三种方法： 

class Annimao():
    pass
class Annimao(object):
    pass
class Annimao:
    pass

三种类方法：

1、实例方法

class Person:
    def __init__(self,age,name):
        self.age = age
        self.name = name
    def speak(self):
        print('说了一段话')

if __name__ == '__main__':

    per = Person(24,'huitao')
    Person.speak()
    per.speak()

Person.speak()不允许类名字调用实例方法

F:开发工具pythonProjectflaskTestvenvscriptspython.exe F:/开发工具/pythonProject/flaskTest/tessss.py
Traceback (most recent call last):
  File "F:开发工具pythonProjectflaskTesttessss.py", line 79, in 
    Person.speak()
TypeError: speak() missing 1 required positional argument: 'self'

Process finished with exit code 1

 去掉Person.speak()

结果：

F:开发工具pythonProjectflaskTestvenvscriptspython.exe F:/开发工具/pythonProject/flaskTest/tessss.py
说了一段话

Process finished with exit code 0

2、类方法

class Employer(object):
    def __init__(self):
        pass
    @classmethod
    def speak(cls):
        print('不允许讲话')

if __name__ == '__main__':

    em = Employer()
    em.speak()
    Employer.speak()

结果：输出了同样的内容

F:开发工具pythonProjectflaskTestvenvscriptspython.exe F:/开发工具/pythonProject/flaskTest/tessss.py
不允许讲话
不允许讲话

Process finished with exit code 0

3、静态方法

class Gun():
    def __init__(self):
        pass
    @staticmethod
    def speak():
        print('又开始说话了')

if __name__ == '__main__':
    g = Gun()
    Gun.speak()
    g.speak()

结果：输出同样内容

F:开发工具pythonProjectflaskTestvenvscriptspython.exe F:/开发工具/pythonProject/flaskTest/tessss.py
又开始说话了
又开始说话了

Process finished with exit code 0

注释：不推荐使用类方法和静态方法，建议使用实例方法