Question

我似乎在将对象附加到其他对象列表时遇到麻烦。尽我所能解释：

我是python的新手，我试图学习类和对象，所以我为自己准备了一个小exe

我的程序中有3个对象：投资者，房屋和市场

在Market课堂上，我仅有的是房屋清单

我有一个由3个投资者组成的列表，每个投资者都有一个作为房屋列表的字段（在第一个 init 处开始为空）

现在，我要做的是显示市场上的房屋清单（我已经完成了）用户输入要购买的房屋的索引，然后程序会将房屋添加到其房屋列表中，并将其从市场中的房屋列表中删除。

现在我的问题似乎是，每当我选择一所房子时，它就会将其添加到所有3个投资者中，而不是添加到特定的投资者中，我不知道为什么 （可能是因为它是ref类型，但我不知道如何克服它：/）

代码：

class Investor:
    def __init__(self, name, budget, houses):
        self.name = name
        self.budget = budget
        self.houses = houses

    def BuyHouse(self, market, houseIndex):
        self.budget -= market.availableHouses(houseIndex).price
        self.houses.append(market.availableHouses[houseIndex])  ## i believe this to be the problem. 
        print(f'Budget left: {self.budget}$')    

    def PrintAllInfo(self): # prints all info for houses.
        counter = 1
        for h in self.houses:
            print(f'{counter}) The House is in: {h.location}\n   The House price is: {h.price}$\n   The House size is: {h.size} sqft')
            counter += 1

class House:
    def __init__(self, location, price, length, width):
        self.location = location
        self.price = price
        self.width = width
        self.length = length

    def PrintThisHouse(self):
        print(f'{self.location}, Price - {self.price}$')

class Market:
    def __init__(self, availableHouses):
        self.availableHouses = availableHouses

    def PrintAllHouses(self):
        print('\nALL ABAILABLE PROPERTIES:\n--------------------------')
        counter = 1
        for h in self.availableHouses:
            print(str(counter) + ' - ', end='')
            counter += 1
            h.PrintThisHouse()

# main #
invHouses = []
investors = [ Investor('Bot1', 100000000, invHouses),
              Investor('Bot2', 100000000, invHouses),
              Investor('Bot3', 100000000, invHouses) ]
# init Houses:
houses = [ House("LA, California",450000,20,10),
           House("IL, Tel Aviv",1000000,5,5),
           House("Rus, Moscow",40000,20,10),
           House("Switz, Zr",125000,7,9),
           House("Fr, Paris",225000,15,4),
           House("Eg, Cairo",75000,15,15),
           House("Pt, Lisbon",100000,10,10),
           House("Ge, Batumi",75000,14,6),
           House("In, New Delhi",50000,20,20),
           House("Ca, Montreal",500000,30,35),
           House("Cambodia, Phnom Pen",15000,9,9),
           House("Uk, London",1000000,10,10) ]

#init Market:
mrkt = Market(houses)


# runs 3 times 1 time for each investor to buy one house.
for inv in investors: # run for all investors
    mrkt.PrintAllHouses() # a func that prints all the houses that are on the market
    selectHouse = (int(input('Enter the house you want to buy: ')) - 1)
    inv.BuyHouse(mrkt, selectHouse)


#after each investor bought a house i want to print for each investor his house(s) in the list
# problem is that now it prints all 3 houses for each one and i dont know why :(
for inv in investors:
    print(f'\nProperties of {inv.name}:')
    inv.PrintAllInfo()
    print('\n**************************')

非常感谢您的帮助

Answer 1

invHouses = []
investors = [ Investor('Bot1', 100000000, invHouses),
              Investor('Bot2', 100000000, invHouses),
              Investor('Bot3', 100000000, invHouses) ]

您有一个由invHouses创建的列表对象。您会将同一对象传递给所有投资者。因此，如果您通过一位投资者将房屋添加到该列表中，那么所有其他投资者也会将该房屋添加到他们的列表中（因为它是同一列表）。

investors = [ Investor('Bot1', 100000000, []),
              Investor('Bot2', 100000000, []),
              Investor('Bot3', 100000000, []) ]

将不同的对象传递给每个投资者。

Answer 2

我认为问题在于您正在将相同的清单invHouses传递给所有投资者。尝试将self.houses初始化为投资者初始状态中的空列表

将对象附加到另一个对象列表

2 个答案: