User Creation Form Mixin

class UserCreationMixin(forms.ModelForm):

    error_messages = {
        'password-mismatch': _(u'Enter the same password as before')
    }

    first_name = forms.CharField(
        label=_(u'First Name'),
        max_length=100,
        help_text=_(u'Enter your first name')
    ),
    last_name = forms.CharField(
        label=_(u'Last Name'),
        max_length=100,
        help_text=_(u'Enter your last name')
    ),
    username = forms.CharField(
        label=_(u'Username'),
        min_length=8,
        max_length=30,
        help_text=_(u'Enter a valid username')
    )
    email = forms.EmailField(
        label=_(u'Email Address'),
        help_text=_(u'Enter a valid email address')
    ),
    password = forms.CharField(
        label=_(u'Password'),
        widget=forms.PasswordInput,
        help_text=_(u'Enter a valid password')
    ),
    confirm_password = forms.CharField(
        label=_(u'Confirm Password'),
        widget=forms.PasswordInput,
        help_text=_(u'Confirm your passwords match')
    )

    def clean_confirm_password(self):
        password = self.cleaned_data['password']
        password2 = self.cleaned_data['confirm_password']

        if password and password2 and password != password2:
            raise forms.ValidationError(
                UserCreationMixin.error_messages['password-mismatch'],
                code='password_mismatch'
            )
            return password2

        self.instance.username = self.cleaned_data['username']
        password_validation.validate_password(password2, self.instance)
        return password2