day13(Alex python)

开始今天的学习。

python支持多继承：

先给一个例子（包括多继承）

# class People: 经典类
class People(object): #新式类
    def __init__(self,name,age):
        self.name = name
        self.age = age
        self.friends = []
        print("--doens't run ")
    def eat(self):
        print("%s is eating..." % self.name)
    def talk(self):
        print("%s is talking..." % self.name)
    def sleep(self):
        print("%s is sleeping..." % self.name)

class Relation(object):
    #def __init__(self,n1,n2):
    #    print("init in relation")
    def make_friends(self,obj): #w1
        print("%s is making friends with %s" % (self.name,obj.name))
        self.friends.append(obj)  #指定obj为对应的内存地址，这样可以保证信息会随着更改而更新
class Man(Relation,People):   #多继承会按照顺序查找父类进行初始化构造函数
    # def __init__(self,name,age,money):
    #     #People.__init__(self,name,age)
    #     super(Man,self).__init__(name,age) #新式类写法
    #     self.money  = money
    #     print("%s 一出生就有%s money" %(self.name,self.money))
    def piao(self):
        print("%s is piaoing ..... 20s....done." % self.name)
    def sleep(self):
        People.sleep(self)
        print("man is sleeping ")
class Woman(People,Relation):
    def get_birth(self):
        print("%s is born a baby...." % self.name)

m1 = Man("Mr.jj",28)
w1 = Woman("Mrs.mm",24)

m1.make_friends(w1)
#Mr.jj is making friends with Mrs.mm
w1.name = "Mr.gg"
print(m1.friends[0].name)
#Mr.gg  如果上面不是obj，而是obj.name这里的m1.friends[0]则不会改变。

这个代码实际跑一边看懂逻辑关系就ok。

下面说一下多继承的区别（经典和新式）：

class A:
    def __init__(self):
        print("A")
class B(A):
    pass
    # def __init__(self):
    #     print("B")
class C(A):
    pass
    # def __init__(self):
    #     print("C")
class D(B,C):
    pass
    # def __init__(self):
    #     print("D")

obj = D()

上述代码可以验证多继承的构造函数顺序（广度优先查找）：D——B——C——A （python3程序执行）

（深度优先查找）：D——B——A——C （python2程序执行）

注：python2中的经典类是按深度优先来继承的；新式类是按广度优先来继承的。

python3中经典类和新式类都是按广度优先来继承。

下面给一个学校的例子，很重要，一定要弄懂！

class School(object):
    def __init__(self,name,addr):
        self.name = name
        self.addr = addr
        self.students =[]
        self.staffs =[]
    def enroll(self,stu_obj):
        print("为学员%s 办理注册手续"%stu_obj.name )
        self.students.append(stu_obj)
    def hire(self,staff_obj):
        self.staffs.append(staff_obj)
        print("雇佣新员工%s" % staff_obj.name)

class SchoolMember(object):
    def __init__(self,name,age,sex):
        self.name = name
        self.age = age
        self.sex = sex
    def tell(self):
        pass

class Teacher(SchoolMember):
    def __init__(self,name,age,sex,salary,course):
        super(Teacher,self).__init__(name,age,sex)
        self.salary = salary
        self.course = course
    def tell(self):
        print('''
        ---- info of Teacher:%s ----
        Name:%s
        Age:%s
        Sex:%s
        Salary:%s
        Course:%s
        '''%(self.name,self.name,self.age,self.sex,self.salary,self.course))

    def teach(self):
        print("%s is teaching course [%s]" %(self.name,self.course))

class Student(SchoolMember):
    def __init__(self,name,age,sex,stu_id,grade):
        super(Student,self).__init__(name,age,sex)
        self.stu_id = stu_id
        self.grade = grade
    def tell(self):
        print('''
        ---- info of Student:%s ----
        Name:%s
        Age:%s
        Sex:%s
        Stu_id:%s
        Grade:%s
        ''' % (self.name, self.name, self.age, self.sex, self.stu_id, self.grade))
    def pay_tuition(self,amount):
        print("%s has paid tution for $%s"% (self.name,amount) )


school = School("老男孩IT","沙河")

t1 = Teacher("Oldboy",56,"MF",200000,"Linux")
t2 = Teacher("Alex",22,"M",3000,"PythonDevOps")

s1 = Student("xiaohua",36,"MF",1001,"PythonDevOps")
s2 = Student("xiaofeng",19,"M",1002,"Linux")


t1.tell()
s1.tell()
school.hire(t1)
school.enroll(s1)
school.enroll(s2)

print(school.students)
print(school.staffs)
school.staffs[0].teach()

for stu in school.students:
    stu.pay_tuition(5000)

今天的内容就这么多，慢慢消化吧。

下面给一个学校的例子，很重要，一定要弄懂！

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