How can i get selected option value in user update form?

Using Django
1

my form.py:
class EditUserForm(HelperForm):
job_role = forms.ModelChoiceField(queryset=Group.objects.all(), required=True)

    USER_TYPE_CHOICES = (
        (False, 'Employee'),
        (True, 'Admin'),
    )
    is_superuser = forms.ChoiceField(label='User Type', choices=USER_TYPE_CHOICES)

    class Meta:
        model = User
        fields = [
            'first_name', 'last_name', 'username', 'email', 'is_superuser', 'job_role'
        ]

    def __init__(self, *args, **kwargs):
        super(EditUserForm, self).__init__(*args, **kwargs)
        # self.fields['job_role'].initial = self.instance.groups.all()      # want to get selected job_role

    def save(self, commit=True):
        user = super(EditUserForm, self).save(commit)
        user.save()
        user.groups.clear()
        user.groups.add(self.cleaned_data.get('job_role'))
        return user

my views.py:

class UserEdit(PermissionRequiredMixin, AjaxUpdateView):
    model = User
    form_class = EditUserForm
    context_object_name = 'user'
    ajax_template_name = 'modal_form.html'
    ajax_form_title = 'Edit User'
    permission_required = ('users.edit_users',)

    def get_data(self):
        return {
            'info': 'Edited user information',
        }

    def get_initial(self):
        initial = super(UserEdit, self).get_initial()
        try:
            job_role = self.get_object().job_role
        except:
            pass
        else:
            initial['job_role'] = job_role.pk
        return initial

    def post(self, request, *args, **kwargs):
        form_data = self.get_form_kwargs()['data']
        job_role_id = form_data.get('job_role')
        job_role_id = 0 if job_role_id == '' else job_role_id
        job_role = Group.objects.filter(id=int(job_role_id)).first()
        user = self.get_object()
        if job_role:
            user.groups.add(job_role)
        return super(UserEdit, self).post(request, args, kwargs)