Move django-based uncloud to top-level

uncloud_pay/helpers.py

@@ -0,0 +1,26 @@
+from functools import reduce
+from datetime import datetime
+from rest_framework import mixins
+from rest_framework.viewsets import GenericViewSet
+from django.utils import timezone
+from calendar import monthrange
+
+def beginning_of_month(year, month):
+    tz = timezone.get_current_timezone()
+    return datetime(year=year, month=month, day=1, tzinfo=tz)
+
+def end_of_month(year, month):
+    (_, days) = monthrange(year, month)
+    tz = timezone.get_current_timezone()
+    return datetime(year=year, month=month, day=days,
+            hour=23, minute=59, second=59, tzinfo=tz)
+
+class ProductViewSet(mixins.CreateModelMixin,
+                     mixins.RetrieveModelMixin,
+                     mixins.ListModelMixin,
+                     GenericViewSet):
+    """
+    A customer-facing viewset that provides default `create()`, `retrieve()`
+    and `list()`.
+    """
+    pass