CODEWITHSUNDEEP
djangodjango-models
Tristan Tran
Tristan Tran

Reputation: 1513

__init__() takes 1 positional argument but 8 were given

class Transaction(models.Model):    
    slug = models.SlugField(max_length=200, db_index=True)
    order_type = models.CharField(verbose_name="Order Method", max_length=200, choices=ORDER_METHODS)
    paid = models.BooleanField(verbose_name="Paid", default=False)
    closed = models.BooleanField(verbose_name="Closed", default=False)
    created = models.DateTimeField(verbose_name="Date of creation", auto_now_add=True)
    id_num = models.IntegerField(verbose_name="Transaction ID", db_index=True)

    def __init__(self):
        super().__init__()
        self.set_transaction_id()

    def set_transaction_id(self):
        self.id_num = int(str(self.created.year) + str(self.created.month) + str(self.created.day).zfill(2) +\
                      str(self.created.hour) + str(self.created.minute).zfill(2) + str(self.created.second).zfill(2))

When I create this model in a view like this:

transaction = Transaction(order_type='Choice_1',
                          paid=False, closed=False)
transaction.save()

I got this error __init__() takes 1 positional argument but 8 were given. The method set_transaction_id() uses the date and time to set the id_num.

Is there something wrong with the way I declare __init__ and using super() or calling set_transaction_id()?

Upvotes: 1

Views: 152

Answers (1)

Lord Elrond
Lord Elrond

Reputation: 16032

You need to use args and kwargs in your __init__:

class Transaction(models.Model):    
    
    ...

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.set_transaction_id()

The parent __init__ method of your model expects the names of each model field as positional or keyword arguments, and when you call super().__init__(), you are trying to call it without any arguments.

Upvotes: 1

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