fix

alkatorapi/views.py

@@ -19,6 +19,7 @@ import json
 import glob
 import PIL.Image
 import random
+import itertools
 from collections import OrderedDict
 
 from .models import (
@@ -410,7 +411,7 @@ def cart_buy(request):
     total_price = 0
     invoice.save()
 
-    for cp in cart_products + [Product.objects.get(id=2)]:
+    for cp in itertools.chain(cart_products, [Product.objects.get(id=2)]):
         ip = InvoiceProduct(
             invoice=invoice,
             price=cp.product.price,