django.py

def formation(request):
    if request.method == 'POST':
        form = ConsultFormationForm(request.POST)
        if form.is_valid():
            theme_choisi = form.cleaned_data['theme']
            duree_min_choisie = form.cleaned_data['duree_min']
            duree_max_choisie = form.cleaned_data['duree_max']

            if theme_choisi is not None:
                if duree_min_choisie != 'no' and duree_max_choisie !='no':
                    list_formations = Formation.objects.filter(theme__libelle__exact=theme_choisi,duree__gt=duree_min_choisie,                      duree__lt=duree_max_choisie)
                else:
                    list_formations = Formation.objects.filter(theme__libelle__exact=theme_choisi)
            else:
                list_formations = Formation.objects.all()
        else:
            form = ConsultFormationForm()
    return render_to_response('catalogue/index.html', {'form': form},context_instance = RequestContext(request))