面向物件編程之——繼承（組合，多型，一切皆物件，面向物件高級之內置函式&方法，反射）

一、組合

組合:把另外一個類的物件賦值給當前物件的屬性
組合表達的是一種有的關系
ps: 繼承：is-a
　　 組合：has-a
　　多型：歸一化，通過繼承實作

class Teacher:
    def __init__(self, name, age, gender, level):
        self.name = name
        self.age = age
        self.gender = gender
        self.level = level

    def tell(self):
        print("%s:%s" % (self.name, self.age))


class Student:
    def __init__(self, name, age, gender):
        self.name = name
        self.age = age
        self.gender = gender


class Course:
    def __init__(self, name, price, period):
        self.name = name
        self.price = price
        self.period = period

    def tell(self):
        print('<%s:%s:%s>' % (self.name, self.price, self.period))


tea1 = Teacher("egon", 18, "male", 10)
stu1 = Student("xxx", 19, "male")

python = Course("python開放", 30000, "3mons")
linux = Course("linux課程", 30000, "3mons")

tea1.courses = [python,linux]
stu1.course = python

# tea,stu  # 超級物件

# stu1.course.tell()
for course_obj in tea1.courses:
    course_obj.tell()

二、多型

同一種事物有多種形態
例如:動物這種事物有多種形態,如人\狗\豬
特性: 我們可以在不考慮某一個物件具體型別的前提下,直接使用該物件

1、父類有的功能,子類一定有

# import abc
#
# class Animal(metaclass=abc.ABCMeta):
#     @abc.abstractmethod
#     def speak(self):
#         pass
#
#     @abc.abstractmethod
#     def run(self):
#         pass
#
# # Animal()  # Animal的作用是用來制定標準的
#
# class People(Animal):
#     def speak(self):
#         print("啊啊啊啊")
#
#     def run(self):
#         print("咻咻咻...")
#
# class Dog(Animal):
#     def giao(self):
#         print("汪汪汪")
#
# class Pig(Animal):
#     def heheng(self):
#         print("哼哼哼")

# peo1=People()
# d1=Dog()
# p1=Pig()

# peo1.jiao()
# d1.giao()
# p1.heheng()




# peo1.speak()
# d1.speak()
# p1.speak()

# def speak(animal):
#     animal.speak()
#
# speak(peo1)
# speak(d1)
#
# speak(p1)

2、鴨子型別:duck

# class People:
#     def speak(self):
#         print("啊啊啊啊")
#
#     def run(self):
#         print("咻咻咻...")
#
# class Dog:
#     def speak(self):
#         print("汪汪汪")
#
#     def run(self):
#         print("狂奔...")
#
# class Pig:
#     def speak(self):
#         print("哼哼")
#
#     def run(self):
#         print("咣咣咣...")
#
#
# peo1=People()
# d1=Dog()
# p1=Pig()


# peo1.run()
# d1.run()
# p1.run()

class Cpu:
    def read(self):
        pass

    def write(self):
        pass

class Process:
    def read(self):
        pass

    def write(self):
        pass

class Disk:
    def read(self):
        pass

    def write(self):
        pass

三、一切皆物件

資料型別 == 類

# x = 11  # x=int(11)
# print(int)

# class Foo:
#     pass
# print(Foo)

x = [1,2,3]  # list([1,2,3])
y = [111,222]  # list([1,2,3])
# x.append(4)
# y.append(3333)

# list.append(x,4)
# list.append(y,333)

# print(x)
# print(y)

print(type(x))

四、面向物件高級

1、內置函式

is   
isinstance判斷型別
 issubclass判斷是否是子類

x = 111

print(type(x) is int)

print(isinstance(x,int))

class Bar:
    pass

class Foo(Bar):
    pass
print(issubclass(Foo,Bar))

2、內置方法

內置方法都是在滿足某種條件下自動觸發的
（1）__str__

class People:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def __str__(self):
        # print('===>')
        return "<%s:%s>" %(self.name,self.age)

obj = People("egon", 18)

print(obj)  # print(obj.__str__())

（2）__del__

class People:
    def __init__(self, name, age,f):
        self.name = name
        self.age = age
        self.f = f

    def __del__(self): #注意運行順序
        print('===>')
        # 回收資源
        self.f.close()

obj = People("egon", 18,open("a.txt",'w',encoding='utf-8'))

del obj
# print('運行完畢...') 

五、反射

反射：獲取程式里的物件，并且把它取出來

dir(物件)

hasattr
getattr
setattr
delattr

用法舉例：

class BlackMedium:
    feature='Ugly'
    def __init__(self,name,addr):
        self.name=name
        self.addr=addr

    def sell_house(self):
        print('%s 黑中介賣房子啦,傻逼才買呢,但是誰能證明自己不傻逼' %self.name)
    def rent_house(self):
        print('%s 黑中介租房子啦,傻逼才租呢' %self.name)

b1=BlackMedium('萬成置地','回龍觀天露園')

#檢測是否含有某屬性
print(hasattr(b1,'name'))
print(hasattr(b1,'sell_house'))

#獲取屬性
n=getattr(b1,'name')
print(n)
func=getattr(b1,'rent_house')
func()

# getattr(b1,'aaaaaaaa') #報錯
print(getattr(b1,'aaaaaaaa','不存在啊'))

#設定屬性
setattr(b1,'sb',True)
setattr(b1,'show_name',lambda self:self.name+'sb')
print(b1.__dict__)
print(b1.show_name(b1))

#洗掉屬性
delattr(b1,'addr')
delattr(b1,'show_name')
delattr(b1,'show_name111')#不存在,則報錯

print(b1.__dict__)

class Foo:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def f1(self):
        print('from f1')


obj = Foo(111, 222)



#反射
# res = dir(obj)
# print(res)
# print(obj.__dict__[res[-1]])

# print(obj.__dict__['x'])
# import re
#
# for attr in dir(obj):
#     if not re.search("^__.*__$",attr):
#         res=getattr(obj,attr)
#         print(res)


# print(hasattr(obj,'x'))
# print(getattr(obj,'xxx',None))  # obj.xxx
# setattr(obj,"xxx",1111)  # obj.xxx = 1111
#
# delattr(obj,"xxx")  # del obj.xxx


# m=__import__("time")
# m.sleep(3)

# getattr(m,'sleep')(3)

---27---

標籤：Python

上一篇：讓python新手快速擺脫小白階段

下一篇：STM32學習筆記之——PWM篇