63.Python：继承

# Python learning
# coding:utf-8

# 1.什么是继承
# 一种新建类的方式，新建的类称为子类或派生类，被继承的类称为父类，又称基类或超类
# Python支持多继承：在Python中，新建的类可以继承一个或多个父类
# 多继承的优点与缺点
#   优点：子类可以同时遗传多个父类的属性，最大限度的重用代码
#   缺点：1.违背人的思维习惯；继承表达的是一种什么“是”什么的关系
#        2.代码可读性变差
#        3.不建议使用多继承，扩展性变差。有可能会引发菱形问题
#           如果涉及到一个子类不可避免的要重用多个父类的属性，应该使用Mixins机制

# 2.为何要用继承：解决类与类之间代码冗余问题

# class Parent1:
#     x = 111
#
#
# class Parent2:
#     pass
#
#
# class Sub1(Parent1):            # 单继承
#     pass
#
#
# class Sub2(Parent1, Parent2):   # 多继承
#     pass
#
#
# print(Sub1.__bases__)
# print(Sub2.__bases__)
# print(Sub1.x)


# 如何实现继承
class OldboyPeople:
    school = 'OLD BOY'

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


class Student(OldboyPeople):

    def choose_course(self):
        print('%s 正在选课' % self.name)


class Teacher(OldboyPeople):

    def __init__(self, name, age, sex, salary, level):
        OldboyPeople.__init__(self, name, age, sex)
        self.salary = salary
        self.level = level

    def score(self):
        print('老师 %s 正在给学生打分' % self.name)


stu_obj = Student('sepia', 20, 'male')
print(stu_obj.__dict__)
print(stu_obj.school)
stu_obj.choose_course()

tea_obj = Teacher('egon', 30, 'male', 100000, 10)
print(tea_obj.__dict__)
print(tea_obj.school)
tea_obj.score()