J'ai du mal à comprendre comment initialiser une classe héritée en python OOP.

Je ne peux pas comprendre quels arguments doivent être passés lorsque je l'initialise. Voici les classes que j'utilise:

class BankAccount:  #parent class

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

    def withdrawal(self, withdraw):
        if withdraw > self.balance:
            raise RuntimeError('Sorry, Insufficient Funds!')
        else:
            print('Withdrawal accepted.')
            self.balance -= withdraw
            show_balance = input('See account balance? enter y or n: ')
            if show_balance == 'y':
                print(self.balance)

    def deposit(self, amt):
        self.balance += amt
        print('Deposit Accepted')
        show_balance = input('See account balance? enter y or n: ')
        if show_balance == 'y':
            print(self.balance)


class MinimumBalanceAccount(BankAccount):        #child class

    minimum_balance = 100

    def __init__(self):
        BankAccount.__init__(self)

    def withdrawal(self, withdraw):
        if self.balance - withdraw < self.minimum_balance:
            print('Error, balance cannot go below minimum value: {}'.format(minimum_balance))
        else:
            self.balance -= withdraw

Mais quand j'essaye d'initialiser la classe enfant:

acc2 = MinimumBalanceAccount('Milind', 1000)    # I am not sure what to pass as arguments here

Python me donne cette erreur:

TypeError                                 Traceback (most recent call last)
<ipython-input-9-85e55fb15340> in <module>
----> 1 acc2 = MinimumBalanceAccount('milind', 1000)

TypeError: __init__() takes 1 positional argument but 3 were given

Que dois-je transmettre comme arguments ?? Qu'est-ce qui ne va pas?

1
Milind Sharma 16 juin 2020 à 11:44

3 réponses

Meilleure réponse

Vous devez passer les arguments requis à la sous-classe et à la superclasse:

class BankAccount:

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

    def withdrawal(self, withdraw):
        if withdraw > self.balance:
            raise RuntimeError('Sorry, Insufficient Funds!')
        else:
            print('Withdrawal accepted.')
            self.balance -= withdraw
            show_balance = input('See account balance? enter y or n: ')
            if show_balance == 'y':
                print(self.balance)

    def deposit(self, amt):
        self.balance += amt
        print('Deposit Accepted')
        show_balance = input('See account balance? enter y or n: ')
        if show_balance == 'y':
            print(self.balance)


class MinimumBalanceAccount(BankAccount):

    minimum_balance = 100

    def __init__(self, owner, balance):
        super().__init__(owner, balance)
        self.minimum_balance = MinimumBalanceAccount.minimum_balance

    def withdrawal(self, withdraw):
        if self.balance - withdraw < self.minimum_balance:
            print('Error, balance cannot go below minimum value: {}'.format(minimum_balance))
        else:
            self.balance -= withdraw

acc2 = MinimumBalanceAccount('Milind', 1000)

Dans ce cas, comme indiqué par @Deceze dans les commentaires, vous pouvez omettre __init__ entièrement:

class MinimumBalanceAccount(BankAccount):        #child class

    minimum_balance = 100

    def withdrawal(self, withdraw):
        if self.balance - withdraw < self.minimum_balance:
            print('Error, balance cannot go below minimum value: {}'.format(minimum_balance))
        else:
            self.balance -= withdraw
2
Reblochon Masque 16 juin 2020 à 08:56

Vous devez également ajouter les paramètres d'initialisation à votre classe enfant lorsque vous définissez la fonction __init__ et la transmettez au parent.

class MinimumBalanceAccount(BankAccount):        #child class

    minimum_balance = 100

    def __init__(self, owner, balance):
        BankAccount.__init__(self, owner, balance)
1
sebastian-ruehmann 16 juin 2020 à 08:48

Compte à solde minimum (compte bancaire): #child class

minimum_balance = 100

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

def withdrawal(self, withdraw):
    if self.balance - withdraw < self.minimum_balance:
        print('Error, balance cannot go below minimum value: {}'.format(minimum_balance))
    else:
        self.balance -= withdraw
0
Trilok Venkat 16 juin 2020 à 09:01