Python类和对象

#两种方式意思相同
class Person:
    pass 
class Person(object):
    pass

class Student:
    #类属性
    name = ''
    age = 0
    subject = []

格式：
def 方法名(self[,parm1,parm2...]):
    pass

class Student:
    # 类属性
    name = 'student'
    age = 0
    subject = []
   # 普通方法
    def study(self):
        print(self.name, '正在学习...') 
xiaoming = Student()
xiaoming.name = 'xiaoming'
xiaoming.study() 

class Student:
    # 类属性
    name = 'student'
    age = 0
    subject = []
   # 普通方法
    def study(self, name):
        print(name, '正在学习...') 
s1 = Student()
s1.study('xiaohong')
 

格式：
@classmethod
def 方法名(cls):
    pass

class Dog:
    dog_type = '阿拉斯加'
   def __init__(self, nickname):
        self.name = nickname
   def dog_run(self):
        print('{}在公园里跑.看起来是一只{}.'.format(self.name, self.dog_type))
   @classmethod
    def dog_sit(cls):
        print(cls.dog_type, '很乖，坐下了') 
dog1 = Dog('肉丸')
dog1.dog_type = '小泰迪'
dog1.dog_run()
Dog.dog_sit() 

class Dog:
    def __init__(self, nickname):
        self.name = nickname
   @staticmethod
    def dog_sit():
        print('很乖，坐下了') 
dog1 = Dog('肉丸')
dog1.dog_sit()
Dog.dog_sit() 
---------------------

格式：
def __方法名__(self):
    pass

class Student:
    #类属性
    name = ''
    age = 0
    subject = [] 
xiaoming = Student()

class Student:
    # 类属性
    name = 'student'
    age = 0
    subject = [] 
xiaoming = Student()
print('类属性:', xiaoming.name)  # 此时是从类中获取的类属性
xiaoming.name = 'xiaoming'  # 因为赋值了，此时变成了对象属性
print('对象属性:', xiaoming.name) 
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