Python-语法学习-{面向对象，魔方，综合应用}

class washer():
    def wash(self):
        print("I can wash clothes")

haier=washer()

print(haier) # <__main__.washer object at 0x000002325A4D3FA0>

haier.wash() # I can wash clothes

self指的是调⽤该函数的对象。

class washer():
    def wash(self):
        print("I can wash clothes")
        print(self)

haier1=washer() 
haier2=washer() 

haier1.wash() #<__main__.washer object at 0x0000018021C3EC10>
print(haier1) #<__main__.washer object at 0x0000018021C3EC10>

haier2.wash() #<__main__.washer object at 0x0000018021C3EC70>
print(haier2) #<__main__.washer object at 0x0000018021C3EC70>

添加+获取

haier1.width=50
print(f"haier's width is {haier1.width}")
# haier's width is 50

class washer():
    def print_info(self):
        print(f"haier's width is {self.width}")

haier1=washer()


haier1.width=50
haier1.print_info()
# haier's width is 50

初始化对象

class washer():
    def __init__(self):
        self.width=50
    def print_info(self):
        print(f"haier's width is {self.width}")

haier1=washer()

haier1.print_info()
# haier's width is 50

class washer():
    def __init__(self,width):
        self.width=width
    def print_info(self):
        print(f"haier's width is {self.width}")

haier1=washer(50)

haier1.print_info()
# haier's width is 50

当使⽤print输出对象的时候，默认打印对象的内存地址。如果类定义了 str ⽅法，那么就会打印从在这个⽅法中 return 的数据。

class washer():
    def __init__(self,width):
        self.width=width
    def print_info(self):
        print(f"haier's width is {self.width}")
    def __str__(self):
        return "This is haier's specification"

haier1=washer(50)

print(haier1)#This is haier's specification

当删除对象时，python解释器也会默认调⽤ del() ⽅法。

class washer():
    def __init__(self,width=50):
        self.width=width
    def print_info(self):
        print(f"haier's width is {self.width}")
    def __str__(self):
        return "This is haier's specification"
    def __del__(self):
        print(f"{self} object have been deleted already")

haier1=washer(50)

del haier1
# This is haier's specification object have been deleted already

这里为什么会这样呢 ，去掉str试试看

class washer():
    def __init__(self,width=50):
        self.width=width
    def print_info(self):
        print(f"haier's width is {self.width}")
    #def __str__(self):
        #return "This is haier's specification"
    def __del__(self):
        print(f"{self} object have been deleted already")

haier1=washer(50)

del haier1
# <__main__.washer object at 0x0000020C25FEAE80> object have been deleted already

__str__会把目标对象替换成return后的语句

class SweetPotato():
    def __init__(self):
        self.cook_time = 0
        self.cook_static = "raw"
        self.cook_condiments = []

    def cook(self, time):
        self.cook_time += time
        if 0 <= self.cook_time < 3:
            self.cook_static = "raw"
        elif 3 <= self.cook_time < 5:
            self.cook_static = "halfcooked"
        elif 5 <= self.cook_time < 8:
            self.cook_static = "baked"
        elif 8 <= self.cook_time:
            self.cook_static = "burnt"

    def __str__(self):
        return f"This sweet potato have been baked for {self.cook_time} minutes,condition is {self.cook_static}," 
               f"the added condiments are {self.cook_condiments}"

    def add_condiments(self,condiments):
        self.cook_condiments.append(condiments)

sp1=SweetPotato()
sp1.cook(5)
sp1.add_condiments("chili")
print(sp1)
# This sweet potato have been baked for 5 minutes,condition is 'baked',the added condiments are ['chili']

class Furniture():
    def __init__(self,name,area):
        self.name=name
        self.area=area
    def __str__(self):
        return self.name

class Home():
    def __init__(self,addr,area):
        self.addr=addr
        self.area=area
        self.free_area=area
        self.furnitures=[]

    def __str__(self):
        return f"home situated {self.addr},area is {self.area},free_area is {self.free_area},furnitures are {self.furnitures}"

    def add_furnitures(self,item):
        if self.free_area > item.area:
            self.furnitures.append(item.name)
            print(f"{item.name} placed successfully")
            self.free_area-=item.area
        else:
            print(f"no enough space to put {item}")

sofa=Furniture("sofa",3)
desk=Furniture("desk",2)
baskbool_court=Furniture("baskbool_court",500)
home=Home("HangZhou",200)
home.add_furnitures(sofa)
home.add_furnitures(desk)
home.add_furnitures(baskbool_court)
print(home)
# #sofa placed successfully
# desk placed successfully
# no enough space to put baskbool_court
# home situated HangZhou,area is 200,free_area is 195,furnitures are ['sofa', 'desk']