Django username already taken error - django

Question

I have an form that allows a user to create a user account.The problem is , whenever a user submit a username that already been taken through the system . The form doesn't raise an error but it does raise an error when a field is missing. Can someone kindly help me
def Registration(request):
form = UserRegistration()
if request.method =='POST':
form = UserRegistration(request.POST)
if form.is_valid():
user = User.objects.create_user(
username=form.cleaned_data['username'],
email=form.cleaned_data['email'],
password=form.cleaned_data['password']
)
user.is_active = True
user.save()
return render(request,'choose.html',{'form':form})
return render(request, 'register.html', {'form': form},)
My forms.py
class UserRegistration(forms.Form):
username = forms.CharField()
email = forms.EmailField(error_messages={'required':'Error Missing Field , Please Fill this Field'})
password = forms.CharField(
widget=forms.PasswordInput(render_value=False)
)
def clean(self):
cleaned_data = super(UserRegistration, self).clean()
username = cleaned_data.get("username")
password = cleaned_data.get("password")
user = User.objects.filter(username=username)
if user :
raise forms.ValidationError(
"That user is already taken , please select another ")
return cleaned_data
My template
<form method ="POST">
{% csrf_token %}
<span id="error">{{form.username.errors}}</span>
<span id="error2">{{form.email.errors}}</span>
<span id="error3">{{form.password.errors}}</span>
{{form.username}}
{{form.email}}
{{form.password}}
<input type = "submit" value= "save" id="box2"/>
</form>

Answer 1

You should use the exists[0] method:
user = User.objects.filter(username=username)
if user.exists():
raise forms.ValidationError("That user is already taken")
Edit:
Try using the clean_username method:
class UserRegistration(forms.Form):
....
def clean_username(self):
username = self.cleaned_data['username']
if User.objects.filter(username=username).exists():
raise forms.ValidationError("That user is already taken")
return username
You could add a Test to make sure it works:
from django.test import TestCase
class TestUniqueUsername(TestCase):
def test_unique_username(self):
User.objects.create(username='test', password='test', email='test#django.com')
form = UserCreationForm(data={'username': 'test'})
self.assertFalse(form.is_valid())
[0] https://docs.djangoproject.com/en/dev/ref/models/querysets/#django.db.models.query.QuerySet.exists

Answer 2

Try this code
class UserRegistration(forms.Form):
username = forms.CharField()
email = forms.EmailField(error_messages={'required':'Error Missing Field , Please Fill this Field'})
password = forms.CharField(
widget=forms.PasswordInput(render_value=False)
)
def clean_username(self):
cleaned_data = self.cleaned_data
username = cleaned_data.get("username")
user = User.objects.filter(username=username)
if user.count() > 0:
raise forms.ValidationError("That user is already taken , please select another ")
return username
This will do the trick.