Python类中私有属性

'''
私有属性

说明：
1.私有属性不能在外面通过实例调用
2.只能够在类里面自己来调用
3.私有属性对外面是隐藏的
'''
class Animal(object):
    hobbie = "meat"
    def __init__(self,name):
        self.name = name
        self.__num = None

    @property
    def total_players(self):
        print(self.__num)

    @total_players.setter
    def total_players(self,num):
        self.__num = num
        print("total players:",self.__num)

d = Animal("Eric")
print(d.total_players)  #None
d.total_players = 4
print(d.total_players)  #total players: 4

d.__num = 9 #这样赋值(不会给类里面的__num私有变量赋值)，只是在d对象中重新创建了一个__num属性，值等于9
print(d.__num)  #9

#其实用(_类名__属性名)还是能调用私有属性
print("OUT:",d._Animal__num)    #OUT: 4