import sys

class TestClass(object):

#定义类属性和私有类属性
__name="wei"
name="whb"

def __init__(self):
    #实例属性不能这样定义
    #self.__salary=8000

    self.salary=8000
    self.id=556600

def __str__(self):
    return "TestClass Description"

def __del__(self):
    pass
    #print("TestClass instance is destroyed")

def __new__(cls):
    #print("TestClass instance is created")
    return object.__new__(cls)  #需要return

def __fun(self):
    print("private function")

#将私有方法封装
def packPrivateFun(self):
    pass
    self.__fun()

@classmethod
def happy(cls,arg):#需要默认参数cls
    print("classmethod worked")

tc1=TestClass()

print(sys.getrefcount(tc1))

tc2=TestClass()

类定义的外部访问不了类的私有属性

print(tc1.__name)

TestClass.__name

类定义的外部访问不了类的私有方法，可以调用封装了私有方法的方法

tc1.__fun()

TestClass.__fun()

tc1.packPrivateFun()

修改实例对象的类属性并对比类的类属性

tc1.name="xia"
tc2.name="lu"
print(tc1.name)
print(tc2.name)
print(TestClass.name)

修改类的类属性

TestClass.name="all"
tc3=TestClass()
print(TestClass.name)
print(tc3.name)
print(tc1.name)
print(tc2.name)

调用类方法

tc1.happy(0)
TestClass.happy(0)