create edit view

view.py

@login_required(login_url='/admin/')
def ad_edit(request,id=None):
    cities = City.objects.filter(status='1')
    adzones = AdZone.objects.all()
    channel_choices = Ad.get_channel_choices()
    ad = get_object_or_none(Ad,pk=id)
    is_edit = True if ad is not None else False
    form = AdForm(instance=ad)
    action = Log.ADDITION if ad is None else Log.CHANGE
    if request.method == 'POST':
        form = AdForm(request.POST,request.FILES,instance=ad)
        if form.is_valid():
            ad = form.save(commit=False)
            ad.user_id = request.user.id
            ad.update_date = datetime.now()
            ad.save()
            Log.set_log(request,ad,action)
            return redirect(reverse('ad_index'))
    return render(request,'ad/ad_edit.html',
                {
                "ad":ad,
                "adzones":adzones,
                "cities":cities,
                "channel_choices":channel_choices,
                "form":form,
                })