Question

class Account():

    def __init__(self,owner,balance):
        self.owner = owner
        self.balance = balance

    def __str__(self):
        return "Account owner : {}\nAccount balance: {}".format(self.owner,self.balance)


    def deposit(amount):
        print ("How much you want to deposit")
        amount = int(input())
        self.balance = (balance) + (amount)
        return "Deposit Accepted\nThe new balance is {}".format(self.balance)


    def withdraw(amount):
        if (self.balance >= amount):
            self.balance = self.balance - amount
            return "Withdrawal Accepted\nThe new balance is {}".format(self.balance)
        else:
            return "Insufficient funds!!"


Account_1 = Account("sammy",500)
print(Account_1)
Account_1.owner
Account_1.balance
Account_1.deposit()
Account_1.withdraw(650)
Account_1.withdraw(300)

在执行此代码时，出现错误，因为“ NameError：未定义名称'self'” 我不明白为什么我会收到这个错误，因为“ self”被用作类的“ self reference”，而我已经做到了。

这段代码只是一个简单的问题，我在研究类和方法时必须解决。

Answer 1

self应该是使用self（例如self.balance）的类中任何方法的第一个参数，因此您的withdraw和deposit方法是缺少self：

def deposit(self,amount):
    print ("How much you want to deposit")
    amount = int(input())
    self.balance += amount
    return "Deposit Accepted\nThe new balance is {}".format(self.balance)


def withdraw(self,amount):
    if (self.balance >= amount):
        self.balance = self.balance - amount
        return "Withdrawal Accepted\nThe new balance is {}".format(self.balance)
    else:
        return "Insufficient funds!!"

请注意，您在self.deposit()语句中缺少该金额。 self方法中的self.balance中还缺少deposit。

Answer 2

deposit和withdraw是成员函数。因此，成员函数的第一个参数应为self。然后，存款函数在函数定义中不需要参数。这是更正的代码。如果为错误发布堆栈跟踪信息，也将很有帮助。这将有助于快速解决此问题。

class Account():

def __init__(self,owner,balance):
    self.owner = owner
    self.balance = balance

def __str__(self):
    return "Account owner : {}\nAccount balance: {}".format(self.owner,self.balance)


def deposit(self):
    print ("How much you want to deposit")
    amount = int(input())
    self.balance = self.balance + amount
    return "Deposit Accepted\nThe new balance is {}".format(self.balance)


def withdraw(self, amount):
    if (self.balance >= amount):
        self.balance = self.balance - amount
        return "Withdrawal Accepted\nThe new balance is {}".format(self.balance)
    else:
        return "Insufficient funds!!"

帐户_1 =帐户（“ sammy”，500）打印（帐户_1）帐户_1。所有者帐户_1。余额 Account_1.deposit（）帐户_1。提款（650） Account_1.withdraw（300）

NameError：由于未定义名称“ self”而引发错误

2 个答案: