python实例属性，类属性，实例名，和类名的传递

python的实例属性的传递

class School:
    def __init__(self, address):
        self.address = address

bj = School('北京总部')
sh = School('上海分部')
sz = School('深圳分部')

class Course(object):
    def __init__(self, name, period, price, school=None):         ##只使用类的初始化构造方法，来初始化实例变量
        self.name = name
        self.period = period
        self.price = price
        self.school = school

py1 = Course('Python', 110, 19999, bj)                         #用到的是实例属性的传递
py2 = Course('Python', 110, 19999, sh)
py3 = Course('Python', 110, 19999, sz)

l1 = Course('Linux', 110, 19999, bj)
l2 = Course('Linux', 110, 19999, sh)

g1 = Course('Go开发', 119, 19999, bj)

class Grade(object):
    def __init__(self, name, people, introduce, course=None):
        self.name = name
        self.people = people
        self.introduce = introduce
        self.course = course

gr1 = Grade('全栈1期',20,'....',py1)
gr2 = Grade('全栈1期',20,'....',py2)
gr3 = Grade('Linux8期',20,'....',l2)


# gr1.people
# gr1.course.price
# gr1.course.school.address
print(gr1.people)
print(gr1.course.price)
print(gr1.course.school.address)

只用类的初始化构造方法来创建实例属性(也可以叫实例变量)，在后面可以像变量一样进行自由传递

类名/实例名 的传递

class Foo(object):

    def __init__(self,age):
        self.age = age

    def display(self):
        print(self.age)

data_list = [Foo(8),Foo(9)]   #类名的传递，加括号实际上就成了实例名了
for item in data_list:
    print(item.display())

obj1=Foo(8)
print(obj1.display())