How can I save an string pk into int pk? - django

Question

I have a problem with a submit form when I want to save the profile ID the form have an error, i dont understand why because in the console all is ok but the form_valis is false, so think because the ModelChoiseField send a pk in sting format so how can i convert the string pk to int pk ?
My Form
class UsuarioForm(forms.ModelForm):
id_perfil = forms.ModelChoiceField(queryset=Perfil.objects.filter(status='1'), label="Perfil" ,empty_label="Seleciona perfil", widget=forms.Select(attrs={'class':'form-control'}))
My Models
class Usuario(models.Model):
id_usuario = models.AutoField(primary_key=True)
nombre = models.CharField(max_length=255)
id_perfil = models.IntegerField()
status = models.CharField(max_length=50)
class Perfil(models.Model):
id_perfil = models.AutoField(primary_key=True)
nombre = models.CharField(max_length=255)
status = models.CharField(max_length=50)
The save method
def save_usuario_form(request, form, template_name):
data = dict()
if request.method == 'POST':
if form.is_valid():
usuario = form.save(commit=False)
if usuario.status == '':
usuario.status = '1'
usuario.id_usuario_alt = '1'
elif usuario.status == '1':
usuario.status = '2'
form.save()
data['form_is_valid']= True
usuarios = Usuario.objects.filter(status='1').order_by('id_usuario')[:5]
data['html_usuario_list'] = render_to_string('back/Modulo_usuarios/usuarios_list.html',{
'usuarios':usuarios
})
else:
data['form_is_valid']= False
context = {'form':form}
data['html_form'] = render_to_string(template_name, context, request=request)
return JsonResponse(data)
The error
All fields are fill and post method is OK