__init__() got an unexpected keyword argument 'user'

Question

i am using Django to create a user and an object when the user is created. But there is an error

__init__() got an unexpected keyword argument 'user'

when calling the register() function in view.py. The function is:

def register(request):  
    '''signup view'''     
    if request.method=="POST":  
        form=RegisterForm(request.POST)  
        if form.is_valid():  
            username=form.cleaned_data["username"]  
            email=form.cleaned_data["email"]  
            password=form.cleaned_data["password"]  
            user=User.objects.create_user(username, email, password)  
            user.save()
            return HttpResponseRedirect('/keenhome/accounts/login/')
        else: 
            form = RegisterForm()      
            return render_to_response("polls/register.html", {'form':form}, context_instance=RequestContext(request))  

    #This is used for reinputting if failed to register    
    else: 
        form = RegisterForm()      
        return render_to_response("polls/register.html", {'form':form}, context_instance=RequestContext(request))

and the object class is:

class LivingRoom(models.Model):
    '''Living Room object'''
    user = models.OneToOneField(User)

    def __init__(self, temp=65):
        self.temp=temp

    TURN_ON_OFF = (
        ('ON', 'On'),
        ('OFF', 'Off'),
    )

    TEMP = (
        ('HIGH', 'High'),
        ('MEDIUM', 'Medium'),
        ('LOW', 'Low'),
    )

    on_off = models.CharField(max_length=2, choices=TURN_ON_OFF)
    temp = models.CharField(max_length=2, choices=TEMP)

#signal function: if a user is created, add control livingroom to the user    
def create_control_livingroom(sender, instance, created, **kwargs):
    if created:
        LivingRoom.objects.create(user=instance)

post_save.connect(create_control_livingroom, sender=User)

The Django error page notifies the error information: user=User.objects.create_user(username, email, password) and LivingRoom.objects.create(user=instance)

I tried to search this problem, finding some cases, but still cannot figure out how to solve it.

Solution 1

You can't do

LivingRoom.objects.create(user=instance)

because you have an __init__ method that does NOT take user as argument.

You need something like

#signal function: if a user is created, add control livingroom to the user    
def create_control_livingroom(sender, instance, created, **kwargs):
    if created:
        my_room = LivingRoom()
        my_room.user = instance

Update

But, as bruno has already said it, Django's models.Model subclass's initializer is best left alone, or should accept *args and **kwargs matching the model's meta fields.

So, following better principles, you should probably have something like

class LivingRoom(models.Model):
    '''Living Room object'''
    user = models.OneToOneField(User)

    def __init__(self, *args, temp=65, **kwargs):
        self.temp = temp
        return super().__init__(*args, **kwargs)

Note - If you weren't using temp as a keyword argument, e.g. LivingRoom(65), then you'll have to start doing that. LivingRoom(user=instance, temp=66) or if you want the default (65), simply LivingRoom(user=instance) would do.

Solution 2

I got the same error.

On my view I was overriding get_form_kwargs() like this:

class UserAccountView(FormView):
    form_class = UserAccountForm
    success_url = '/'
    template_name = 'user_account/user-account.html'

def get_form_kwargs(self):
    kwargs = super(UserAccountView, self).get_form_kwargs()
    kwargs.update({'user': self.request.user})
    return kwargs

But on my form I failed to override the init() method. Once I did it. Problem solved

class UserAccountForm(forms.Form):
    first_name = forms.CharField(label='Your first name', max_length=30)
    last_name = forms.CharField(label='Your last name', max_length=30)
    email = forms.EmailField(max_length=75)

    def __init__(self, *args, **kwargs):
        user = kwargs.pop('user')
        super(UserAccountForm, self).__init__(*args, **kwargs)

Solution 3

LivingRoom.objects.create() calls LivingRoom.__init__() - as you might have noticed if you had read the traceback - passing it the same arguments. To make a long story short, a Django models.Model subclass's initializer is best left alone, or should accept *args and **kwargs matching the model's meta fields. The correct way to provide default values for fields is in the field constructor using the default keyword as explained in the FineManual.

Comments

[noben]

Yeah, the problem is from the __init__() function, but why this function does NOT take user as argument?

[shad0w_wa1k3r]

Because the function "init" has only 2 acceptable variables def __init__(self, temp=65), self (class instance) & temp. Also, the class variable "user" is not defined for that instance as yet.

[ViaTech]

Just providing a note. I'm pretty sure if you were to call super(UserAccountForm, self).__init__(*args, **kwargs) before user = kwargs.pop('user'), there would be an error. I have been running into issues with this for a bit and eventually just started passing actual args into __init__, but if you are saying this works, I'm feeling that is why.