世界上肯定是先出现各种各样的实际存在的物体，然后随着人类文明的发展，人类站在不同的角度总结出了不同的种类，比如
人类、动物类、植物类等概念。也就说，对象是具体的存在，而类仅仅只是一个概念，并不真实存在，比如你无法告诉我人类
具体指的是哪一个人这与函数的使用是类似的：先定义函数，后调用函数，类也是一样的：在程序中需要先定义类，后调用类。不一样的是：调用
函数会执行函数体代码返回的是函数体执行的结果，而调用类会产生对象，返回的是对象
按照上述步骤，我们来定义一个类
#在Python中程序中的类用class关键字定义，而在程序中特征用变量标识，技能用函数标识，因而类中最常见的无非是：变量和函数的定义
class LuffyStudent:
school=‘luffy‘
def __init__(self,name,age):
self.name = name
self.age = age
def learn(self):
print(‘is learning‘)
def eat(self):
print(‘%s is eating‘ %self.name)
def sleep(self):
print(‘%s is sleeping‘ %self.name)
def __del__(self):
print("running del method, this person must be died.")
# 后产生对象
stu1=LuffyStudent(‘alex‘,18)
stu2=LuffyStudent(‘li‘,28)
stu3=LuffyStudent(‘hy‘,38)
print(LuffyStudent.__dict__)
stu1.eat()
stu2.eat()
stu3.sleep()
print(‘--end program--‘)
输出结果
{‘__module__‘: ‘__main__‘, ‘school‘: ‘luffy‘, ‘__init__‘: <function LuffyStudent.__init__ at 0x00000000028CB8C8>, ‘learn‘: <function LuffyStudent.learn at 0x000000001272FB70>,
‘eat‘: <function LuffyStudent.eat at 0x000000001272FBF8>, ‘sleep‘: <function LuffyStudent.sleep at 0x000000001272FC80>, ‘__del__‘: <function LuffyStudent.__del__ at 0x000000001272FD08>,
‘__dict__‘: <attribute ‘__dict__‘ of ‘LuffyStudent‘ objects>, ‘__weakref__‘: <attribute ‘__weakref__‘ of ‘LuffyStudent‘ objects>, ‘__doc__‘: None}
alex is eating
li is eating
hy is sleeping
--end program--
running del method, this person must be died.
running del method, this person must be died.
running del method, this person must be died.
注意：
print(LuffyStudent.school) # 查 # luffy LuffyStudent.school=‘Oldboy‘ # 改 print(LuffyStudent.school) # 查 # Oldboy LuffyStudent.sex=‘male‘ # 增 print(LuffyStudent.sex) # male del LuffyStudent.sex # 删 print(‘--end program--‘)
#执行__init__,stu1.name=‘alex‘，
# 很明显也会产生对象的名称空间可以用stu1.__dict__查看，查看结果为
print(stu1.__dict__)
print(stu1.name) #查，等同于stu1.__dict__[‘name‘]
stu1.name=‘王三炮‘ #改，等同于stu1.__dict__[‘name‘]=‘王三炮‘
print(stu1.__dict__)
stu2.course=‘python‘ #增，等同于stu1.__dict__[‘course‘]=‘python‘
print(stu2.__dict__)
del stu2.course #删，等同于stu2.__dict__.pop(‘course‘)
print(stu2.__dict__)
#输出结果：
alex
{‘name‘: ‘王三炮‘, ‘age‘: 18}
{‘name‘: ‘li‘, ‘age‘: 28, ‘course‘: ‘python‘}
{‘name‘: ‘li‘, ‘age‘: 28}
原文：https://www.cnblogs.com/xiao-apple36/p/9127525.html