Introduce custom ProductViewSet preventing customer from updating

products

uncloud/uncloud_pay/helpers.py

@@ -1,10 +1,11 @@
 from functools import reduce
+from rest_framework import mixins
+from rest_framework.viewsets import GenericViewSet
 from .models import Bill, Payment, PaymentMethod
 
 def sum_amounts(entries):
     return reduce(lambda acc, entry: acc + entry.amount, entries, 0)
 
-
 def get_balance_for(user):
     bills = sum_amounts(Bill.objects.filter(owner=user))
     payments = sum_amounts(Payment.objects.filter(owner=user))
@@ -18,3 +19,14 @@ def get_payment_method_for(user):
             return method
 
     return None
+
+
+class ProductViewSet(mixins.CreateModelMixin,
+                   mixins.RetrieveModelMixin,
+                   mixins.ListModelMixin,
+                   GenericViewSet):
+    """
+    A customer-facing viewset that provides default `create()`, `retrieve()`
+    and `list()`.
+    """
+    pass