继承与派生

'''
# 1、什么是继承？
#     继承一种新建类的的方式，在python中支持一个儿子继承多个爹
#     新建的类称为子类或者派生类，
#     父类又可以称为基类或者超类
#
#     子类会”遗传“父类的属性
#
# 2、为什么要用继承
#     减少代码冗余
#
# 3、怎么用继承：
# '''
#
# 单继承与多继承（ps：再项目中我们一般最常用的是单继承）：
# class ParentClass1:
#     pass
#
# class ParentClass2:
#     pass
#
# class SubClass1(ParentClass1): #单继承，括号内的类是基类，SubClass1是派生类。
#     pass
#
# class SubClass2(ParentClass1,ParentClass2):
#     pass


# 查看从左边起第一个基类

# print(SubClass2.__base__) #<class '__main__.ParentClass1'>

# 查看所有基类

# print(SubClass2.__bases__)  #(<class '__main__.ParentClass1'>, <class '__main__.ParentClass2'>)

# 如果没有指定基类则会默认继承object类，它是所有python类的基类。

'''
 二、继承关系
继承是类与类之间的关系，寻找这种关系需要先抽象再继承

示例1中 把两个类中相同的部分单独建一个类（父类），创建子类时把父类导入。
'''
# 运用继承
# 示例1：
# class OidboyPepol:
#
#     school='oldboy'
#
#     def __init__(self,name,age,sex):
#         self.name=name
#         self.age=age
#         self.sex=sex
#
# class Teacher(OidboyPepol):
#     def change_score(self):
#         print('teacher %s is changing score '%self.name)
#
# class Student(OidboyPepol):
#     def choose(self):
#         print('stydent %s choose course ' % self.name)
#
# tel=Teacher('egon',18,'male')
#
# stu1=Student('alex',73,'female')

# 基于继承看属性查找：
# 新式类严格遵循这一原则！！
# 查找顺序：自己名称空间—》 自己的类空间--》父类的名称空间—》object
# 示例：
# class Foo:
#     def f1(self):
#         print('Foo.f1')
#     def f2(self):
#         print('Foo.f2')
#         self.f1()

# class Bar(Foo):
#     def f1(self):
#         print('Bar.f1')
# obj=Bar()

# obj.f1()

# 派生：

#子类定义自己新的属性，如果与父类同名，自类会以自己的为准。

# class OldboyPeople:
#     school = 'oldboy'
#
#     def __init__(self, name, age, sex):
#         self.name = name
#         self.age = age
#         self.sex = sex
#
#     def f1(self):
#        print('爹的f1')
#
#
# class OldboyTeacher(OldboyPeople):
#     def change_score(self):
#         print('teacher %s is changing score' %self.name)
#
#     def f1(self):
#         print('儿子的f1')
#
# tea1 = OldboyTeacher('egon', 18, 'male')
# tea1.f1()  #儿子的f1




# 在子类派生出的新方法中重用父类的功能
#方式一：指名道姓地调用（其实与继承没有什么关系的）
# OldboyPeople.__init__(self,name, age, sex)

# class OldboyPeople:
#     school = 'oldboy'
#
#     def __init__(self, name, age, sex):
#         self.name = name
#         self.age = age
#         self.sex = sex
#
#     def tell_info(self):
#         print("""
#         ===========个人信息==========
#         姓名：%s
#         年龄：%s
#         性别：%s
#         """ %(self.name,self.age,self.sex))
#
#
# class OldboyTeacher(OldboyPeople):
#     #            tea1,'egon', 18, 'male', 9, 3.1
#     def __init__(self, name, age, sex, level, salary):
#         # self.name = name
#         # self.age = age
#         # self.sex = sex
#         OldboyPeople.__init__(self,name, age, sex)
#
#         self.level = level
#         self.salary = salary
#
#     def tell_info(self):
#         OldboyPeople.tell_info(self)
#         print("""
#         等级：%s
#         薪资：%s
#         """ %(self.level,self.salary))
#
# tea1 = OldboyTeacher('egon', 18, 'male', 9, 3.1)
# # print(tea1.name, tea1.age, tea1.sex, tea1.level, tea1.salary)
#
#
# tea1.tell_info()



#方式二：super()调用（严格依赖于继承）
#super()的返回值是一个特殊的对象，该对象专门用来调用父类中的属性

#了解：在python2中，需要super(自己的类名,self)
# class OldboyPeople:
#     school = 'oldboy'
#
#     def __init__(self, name, age, sex):
#         self.name = name
#         self.age = age
#         self.sex = sex
#
#     def tell_info(self):
#         print("""
#         ===========个人信息==========
#         姓名：%s
#         年龄：%s
#         性别：%s
#         """ %(self.name,self.age,self.sex))
#
#
# class OldboyTeacher(OldboyPeople):
#     #            tea1,'egon', 18, 'male', 9, 3.1
#     def __init__(self, name, age, sex, level, salary):
#         # OldboyPeople.__init__(self,name, age, sex)
#         super(OldboyTeacher,self).__init__(name,age,sex)
#
#         self.level = level
#         self.salary = salary
#
#     def tell_info(self):
#         # OldboyPeople.tell_info(self)
#         super().tell_info()
#         print("""
#         等级：%s
#         薪资：%s
#         """ %(self.level,self.salary))
#
# tea1 = OldboyTeacher('egon', 18, 'male', 9, 3.1)
# # print(tea1.name, tea1.age, tea1.sex, tea1.level, tea1.salary)
# tea1.tell_info()


'''
1、新式类：
    继承object的类，以及该类的子类，都是新式类

    在python3中，如果一个类没有指定继承的父类，默认就继承object
    所以说python3中所有的类都是新式类

2、经典类(只有在python2才区分经典类与新式类)：
    没有继承object的类，以及该类的子类，都是经典类


在菱形继承的背景下，查找属性
1、经典类：深度优先
2、新式类：广度优先

'''

# class A:
    # def test(self):
    #     print('from A')
    # pass

# class B(A):
    # def test(self):
    #     print('from B')
    # pass

# class C(A):
    # def test(self):
    #     print('from C')
#     pass
# class D(B):
    # def test(self):
    #     print('from D')
    # pass

# class E(C):
    # def test(self):
    #     print('from E')
#     pass
#
# class F(D,E):
    # def test(self):
    #     print('from F')
    # pass
# f1=F()
# f1.test()

# F->D->B->E->C-A->object

# print(F.mro())











# class OidboyPepol:
#
#     school='oldboy'
#
#     def __init__(self,name,age,sex):
#         self.name=name
#         self.age=age
#         self.sex=sex
#
# class Teacher(OidboyPepol):
#     def __init__(self,name,age,sex,level,salary):
#
#         self.level=level
#         self.salary=salary
#         super().__init__(name,age,sex)
#     def change_score(self):
#         print('teacher %s is changing score '%self.name)
#
# class Student(OidboyPepol):
#     def choose(self):
#         print('stydent %s choose course ' % self.name)
#
# tel=Teacher('egon',18,'male',9,3.1)
# print(tel.name,tel.sex,tel.age,tel.level,tel.salary)
# stu1=Student('alex',73,'female')