類問題 - 程序按預期工作，但 Visual Studio 代碼突出顯示語法錯誤

Question

我的程序按預期工作，當我執行從賬戶 1 到賬戶 2 的轉賬時，它會輸出正確的值。

但是，Visual Studio 代碼在紅色下划線“self”（例如告訴我“'Account' 實例沒有'filepath' 成員）

你能幫我理解我做錯了什么嗎？ 非常感謝！

這是我的代碼和下面的 output，非常感謝！

class Account:
 
    def __init__(self):
        filepath=self.filepath  #self is underlined here
        with open(filepath,"r") as file:
            self.balance = int(file.read())
    
    def withdraw(self, amount):
        self.balance -= amount
    
    def deposit(self, amount):
        self.balance += amount
 
    def transfer(self, amount, receiver):
        self.newbalance = self.balance - amount
        receiver.newbalance = receiver.balance + amount
        print(self.accountname,"balance is",self.balance) #self is underlined here
        print(receiver.accountname,"balance is",receiver.balance)
        print(self.accountname,"transfering",amount,"to",receiver.accountname) #self is underlined here
        print(self.accountname, "new balance is",self.newbalance) #self is underlined here
        print(receiver.accountname, "new balance is",receiver.newbalance) 
 
class Louis(Account):
 
    accountname = "Louis" 
    filepath = "louis.txt"
 
class Romain(Account):
 
    accountname = "Romain"
    filepath = "romain.txt"
 
romain = Romain()
louis = Louis()
 
romain.transfer(99,louis)

Output

Romain balance is 2000
Louis balance is 1000
Romain transfering 99 to Louis
Romain new balance is 1901
Louis new balance is 1099

Answer 1

問題是您只在子類中設置filepath 。 如果您嘗試創建一個Account object 而不是Louis或Romain ，或者您使用另一個未設置filepath的子類，您將收到錯誤消息。 VS Code 無法知道您從不這樣做，它只是自行分析 class。

Answer 2

我相信 inheritance 在這里會導致一些混亂。 雖然 Louis 和 Roman 都初始化了filepath ，但賬戶基礎 class 從未初始化過filepath 。 Visual Studio 將此標記為語法錯誤，因為如果您已初始化 Account 的實例，您的代碼將引發AttributeError 。 例如：

class Account:    
     
    def __init__(self):    
        filepath=self.filepath  #self is underlined here    
        with open(filepath,"r") as file:    
            self.balance = int(file.read())    
        
    def withdraw(self, amount):    
        self.balance -= amount    
        
    def deposit(self, amount):    
        self.balance += amount    
     
    def transfer(self, amount, receiver):    
        self.newbalance = self.balance - amount    
        receiver.newbalance = receiver.balance + amount    
        print(self.accountname,"balance is",self.balance) #self is underlined here    
        print(receiver.accountname,"balance is",receiver.balance)    
        print(self.accountname,"transfering",amount,"to",receiver.accountname) #self is underlined here    
        print(self.accountname, "new balance is",self.newbalance) #self is underlined here    
        print(receiver.accountname, "new balance is",receiver.newbalance)     
     
class Louis(Account):    
     
    accountname = "Louis"     
    filepath = "louis.txt"    
     
class Romain(Account):    
     
    accountname = "Romain"    
    filepath = "romain.txt"    
     
romain = Romain()    
louis = Louis()    
     
romain.transfer(99,louis)    
    
account = Account() 

Output

Romain balance is 2000
Louis balance is 1000
Romain transfering 99 to Louis
Romain new balance is 1901
Louis new balance is 1099
Traceback (most recent call last):
  File "/home/test.py", line 38, in <module>
    account = Account()
  File "/home/test.py", line 4, in __init__
    filepath=self.filepath  #self is underlined here
AttributeError: 'Account' object has no attribute 'filepath'

Answer 3

您的文件路徑是 Class filepath而不是實例變量

Louis 和 Romain 需要是Account的實例

class Account:    
     
    def __init__(self, accountname, filepath):
        self.filepath = filepath
        self.accountname = accountname
        self.balance = 0
        with open(self.filepath,"r") as file:    
            self.balance = int(file.read())    
        
    def withdraw(self, amount):    
        self.balance -= amount    
        
    def deposit(self, amount):    
        self.balance += amount    
     
    def transfer(self, amount, receiver):    
        self.newbalance = self.balance - amount    
        receiver.newbalance = receiver.balance + amount    
        print(self.accountname,"balance is",self.balance)
        print(receiver.accountname,"balance is",receiver.balance)    
        print(self.accountname,"transfering",amount,"to",receiver.accountname)
        print(self.accountname, "new balance is",self.newbalance)
        print(receiver.accountname, "new balance is",receiver.newbalance)     
    
romain = Account("Romain", "romain.txt")
louis = Account("Louis", "louis.txt")

romain.transfer(99,louis)