117 对象的属性查找顺序

 

目录

 

一、属性查找

• 先从对象自己的名称空间找，没有则去类中找，如果类也没有则报错

class OldboyStudent:
    school = 'oldboy'
    count = 0
    aa = 10

    def __init__(self, x, y, z):  #会在调用类时自动触发
        self.name = x  # stu1.name='耗哥'
        self.age = y  # stu1.age=18
        self.sex = z  # stu1.sex='male'
        OldboyStudent.count += 1
        #         self.count += 5
        self.aa = 1

    def choose_course(self):
        print('is choosing course')

print(OldboyStudent.count)

0

stu1 = OldboyStudent('nick', 18, 'male')
print(stu1.count)

1

stu2 = OldboyStudent('sean', 17, 'male')
print(stu2.count)

2

stu3 = OldboyStudent('tank', 19, 'female')
print(stu3.count)

3

print(OldboyStudent.count)

3

print(stu1.name)

nick

• 由于上述修改的是类属性，类属性的count已经被修改为3，所以其他实例的count都为3

print(stu1.count)

3

print(stu2.count)

3

print(stu3.count)

3

• 由于aa是私有属性，因此stu们都会用自己私有的aa，不会用类的aa

print(stu1.__dict__)

{'name': 'nick', 'age': 18, 'sex': 'male', 'aa': 1}

print(stu2.__dict__)

{'name': 'sean', 'age': 17, 'sex': 'male', 'aa': 1}

print(stu3.__dict__)

{'name': 'tank', 'age': 19, 'sex': 'female', 'aa': 1}