views.py
def index(request):
allProds = []
catprods = Allmusic.objects.values('category', 'sno')
cats = {item['category'] for item in catprods}
for cat in cats:
prod = Allmusic.objects.filter(category=cat)
n = len(prod)
nSlides = n // 4 + ceil((n / 4) - (n // 4))
allProds.append([prod, range(1, nSlides), nSlides])
params = {'allProds':allProds}
return render(request,'index.html',params)
index.html
For More details you can see my stackoverflow page