python - Anonymous user error -

i'm trying save form data anonymous user, below error when trying save form data in createview". i'm not clear issue is?

valueerror: cannot assign "<simplelazyobject: <django.contrib.auth.models.anonymoususer object @ 0x11126bc18>>": "euser.user" must "user" instance. 

models:

class euser(models.model):     online_account = models.booleanfield()      supplier1 = models.onetoonefield(supplieraccount)     supplier2 = models.onetoonefield(supplieraccount)     supplier3 = models.onetoonefield(supplieraccount)      address = models.onetoonefield(address)     user = models.foreignkey(settings.auth_user_model)  class supplieraccount(models.model):     supplier = models.foreignkey(supplier)     username = models.charfield(max_length=255)     password = models.charfield(max_length=255) 

form:

class servicetypeform(forms.modelform):     # bool_choices = ((false, 'no'), (true, 'yes'))      # online_account = forms.booleanfield(widget=forms.radioselect(choices=bool_choices))      def __init__(self, *args, **kwargs):         super(servicetypeform, self).__init__(*args, **kwargs)         self.fields['service_type'].initial = 'd'      class meta:         model = euser         fields = ('service_type', 'online_account') 

view:

class servicetypeview(createview):     form_class = servicetypeform     template_name = "standard_form.html"     success_url = '/'      def form_valid(self, form):         form.instance.user = self.request.user         super().form_valid(form)         online_account = form.cleaned_data['online_account']         if online_account:             return redirect('../online')         else:             return redirect('../address') 

if user not logged in, request.user anonymous user. doesn't make sense assign anonymous user form.instance.user, because anonymous user not exist in database or have primary key.

how change code depends on how want application work.

if want allow anonymous users create service types,

if self.request.user.is_authenticated():     form.instance.user = self.request.user 

for work, need change user field make optional.

user = models.foreignkey(settings.auth_user_model, blank=true, null=true) 

after making change, you'll need run makemigrations , migrate, update database.

another option restrict view logged in users. in django 1.9+, can loginrequiredmixin.

from django.contrib.auth.mixins import loginrequiredmixin  class servicetypeview(loginrequiredmixin, createview):     ...