Python 小栈_17：Python 面向对象及静态属性、类方法、静态方法

今日所学：

 

一、面向对象作业

1、学校类

class School:
    def __init__(self,name,addr,type):
        self.name=name
        self.addr=addr
        self.type=type

    def test(self,name):
        print("%s 正在举行考试" %self.name)

    def athlete(self,name):
        print("%s 正在举行运动会" %self.name)

    def zhao_sheng(self,name):
        print("%s 正在招生" %self.name)

print(School.__dict__)
s1=School("清华大学","北京","公立大学")
print(s1.name)
print(s1.__dict__)
s1.test("清华大学")


>>>
{'__module__': '__main__', '__init__': <function School.__init__ at 0x000001F8E737B4C0>, 'test': <function School.test at 0x000001F8E737B550>, 'athlete': <function School.athlete at 0x000001F8E737B5E0>, 'zhao_sheng': <function School.zhao_sheng at 0x000001F8E737B670>, '__dict__': <attribute '__dict__' of 'School' objects>, '__weakref__': <attribute '__weakref__' of 'School' objects>, '__doc__': None}
清华大学
{'name': '清华大学', 'addr': '北京', 'type': '公立大学'}
清华大学 正在举行考试

 

2、老师类

#老师类
class Teacher:
    def __init__(self,name,gender,age,subject):
        self.name=name
        self.gender=gender
        self.age=age
        self.subject=subject

    def teach_class(self,name,subject):
        print("%s教%s科目" %(self.name,self.subject))

    def give_homework(self,name):
        print("%s布置了作业" %self.name)

t1=Teacher("happy","female",30,"英语")
print(Teacher.__dict__)
print(t1.name)
t1.teach_class("happy","英语")
t1.give_homework("happy")


>>>
{'__module__': '__main__', '__init__': <function Teacher.__init__ at 0x00000283134CB4C0>, 'teach_class': <function Teacher.teach_class at 0x00000283134CB550>, 'give_homework': <function Teacher.give_homework at 0x00000283134CB5E0>, '__dict__': <attribute '__dict__' of 'Teacher' objects>, '__weakref__': <attribute '__weakref__' of 'Teacher' objects>, '__doc__': None}
happy
happy教英语科目
happy布置了作业

 

3、课程类

#课程类
class Course:
    def __init__(self,kind,price,teacher):
        self.kind=kind
        self.price=price
        self.teacher=teacher

    def set_course(self,teacher,kind):
        print("%s设置了%s课" %(self.teacher,self.kind))

    def set_price(self,kind,price):
        print("%s课的价钱为%s" %(self.kind,self.price))

c1=Course("python",1000,"happy")
print(Course.__dict__)
print(c1.__dict__)
print(c1.kind)
c1.set_course("happy","python")
c1.set_price("python","1000")


>>>
{'__module__': '__main__', '__init__': <function Course.__init__ at 0x000001CC4078B4C0>, 'set_course': <function Course.set_course at 0x000001CC4078B550>, 'set_price': <function Course.set_price at 0x000001CC4078B5E0>, '__dict__': <attribute '__dict__' of 'Course' objects>, '__weakref__': <attribute '__weakref__' of 'Course' objects>, '__doc__': None}
{'kind': 'python', 'price': 1000, 'teacher': 'happy'}
python
happy设置了python课
python课的价钱为1000

 

二、静态属性、类方法和静态方法

1、静态属性

用法：封装函数属性，跟实例绑定，可访问实例属性也可访问类属性

class Course:
    def __init__(self,kind,price,teacher):
        self.kind=kind
        self.price=price
        self.teacher=teacher

    def set_course(self,teacher,kind):
        print("%s设置了%s课" %(self.teacher,self.kind))


    @property     #调用静态属性
    def set_price(self):     #property中自动有self参数，一般用return来返回值，且在调用时不用加括号，即不用再加任何参数
        return "%s课的价钱为%s" %(self.kind,self.price)

c1=Course("python",1000,"happy")
print(Course.__dict__)
print(c1.__dict__)
print(c1.kind)
c1.set_course("happy","python")
print(c1.set_price)    #像调实例数据属性一样去调用函数属性，封装你的逻辑，实际是底层做了转换
print(Course.set_price)    #类和实例都可调用


>>>
{'__module__': '__main__', '__init__': <function Course.__init__ at 0x000001B25CCDB4C0>, 'set_course': <function Course.set_course at 0x000001B25CCDB550>, 'set_price': <property object at 0x000001B25CCE8040>, '__dict__': <attribute '__dict__' of 'Course' objects>, '__weakref__': <attribute '__weakref__' of 'Course' objects>, '__doc__': None}
{'kind': 'python', 'price': 1000, 'teacher': 'happy'}
python
happy设置了python课
python课的价钱为1000
<property object at 0x000001B25CCE8040>

 

2、类方法

类方法即不用跟实例捆绑在一起的方法，只是类调用自己的属性。在定义属性时会自动有cls参数。

class Student:
    tag="中学学生"
    def __init__(self,name,gender,age):
        self.name=name
        self.gender=gender
        self.age=age

    def have_class(self,name):
        print("%s在上课" %self.name)


    @classmethod
    def tell_info(cls):
        print(cls)
        print(cls.tag)

Student.tell_info()    #只用来查看类的信息，不用再经过实例即可调用


>>>
<class '__main__.Student'>
中学学生

 

3、静态方法

只是名义上的归属类管理，不能使用类变量和实例变量。没有任何参数。

class Classroom:

    def __init__(self,classroom,grade,amount):
        self.classroom=classroom
        self.grade=grade
        self.amount=amount
    @staticmethod     #一个类的工具包，来调用跟类和变量都没有关系的属性
    def have_class(x,y):
        print("%s班有%s人" %(x,y))

    def test(x,y):
        print(x,y)

c1=Classroom("五班","高二级",40)
print(Classroom.__dict__)    #在类字典中，have_class函数属于staticmethod object，而test函数则属于function
c1.have_class(1,2)
print(c1.__dict__)   #在实例字典中只有数据属性
# c1.test(1,2)   #因为test函数没有self变量，而python又会自动传入实例本身，因此会报错


>>>
{'__module__': '__main__', '__init__': <function Classroom.__init__ at 0x000001BCB042B4C0>, 'have_class': <staticmethod object at 0x000001BCB03EAA60>, 'test': <function Classroom.test at 0x000001BCB042B5E0>, '__dict__': <attribute '__dict__' of 'Classroom' objects>, '__weakref__': <attribute '__weakref__' of 'Classroom' objects>, '__doc__': None}
1班有2人
{'classroom': '五班', 'grade': '高二级', 'amount': 40}

 

以上。