类关系/self/特殊成员

1.依赖关系
　　在方法中引入另一个类的对象
2.关联关系、聚合关系、组合关系

#废话少说 直接上代码===>选课系统

# coding:utf-8


class Student(object):
    def __init__(self, sid, name, addr):
        self.sid = sid
        self.name = name
        self.addr = addr
        self.course = []

    def get_info(self):
        for el in self.course:
            print(el.cid, el.title, el.teacher.tid,
                  el.teacher.name,el.teacher.phone)

    def add_course(self, course):
        self.course.append(course)


class Course(object):
    def __init__(self, cid, title):
        self.cid = cid
        self.title = title
        self.course_list = []
        self.teacher = ''

    def get_info(self, course):
        pass

    def setting_teacher(self, teacher):
        self.teacher = teacher


class Teacher(object):
    def __init__(self, tid, name, phone):
        self.tid = tid
        self.name = name
        self.phone = phone


t1 = Teacher(11, "张三", 1815786)
t2 = Teacher(22, "李四", 10086)

c1 = Course(1, "python1")
c1.setting_teacher(t1)
c2 = Course(2, "python2")
c2.setting_teacher(t2)
c3 = Course(3, "python3")
c3.setting_teacher(t1)
s1 = Student(111, "alex", "北京")
s1.add_course(c1)
s1.add_course(c2)
s1.add_course(c3)
s1.get_info()

3.继承关系，实现关系
　　#可哈希:内部是否有哈希算法
　　__hash__
　　默认的类和对象都是可哈希的
　　self就是你访问方法的那个对象. 先找自己, 然后在找父类的.

废话少说 上代码

class Base:
    def __init__(self, num):
        self.num = num

    def func1(self):
        print(self.num)
        self.func2()

    def func2(self):
        print(111, self.num)


class Foo(Base):
    def func2(self):
        print(222, self.num)


# Base(1) 1 111 1
# Base(2) 2 111 2
# Foo(3)  3 222 3
# 这里面注意换行
lst = [Base(1), Base(2), Foo(3)]
for obj in lst:
    obj.func1()  # 那笔来吧. 好好算.

4.特殊成员(__init__())
　　即带双下划线的
　　1.类名() __init__构造方法
　　2.对象() __call__() python 特有的