diff --git a/sigi/apps/utils/mixins.py b/sigi/apps/utils/mixins.py
index 9509d98..9964e59 100644
--- a/sigi/apps/utils/mixins.py
+++ b/sigi/apps/utils/mixins.py
@@ -63,9 +63,7 @@ class LabeledResourse(resources.ModelResource):
         fields = self.get_fields()
         if self.selected_fields:
             fields = [
-                f
-                for f in fields
-                if self.get_field_name(f) in self.selected_fields
+                f for f in fields if self.get_field_name(f) in self.selected_fields
             ]
         return fields
 
@@ -84,9 +82,7 @@ class ValueLabeledResource(LabeledResourse):
 
 class CartExportMixin(ExportMixin):
     to_encoding = "utf-8"
-    import_export_change_list_template = (
-        "admin/cart/change_list_cart_export.html"
-    )
+    import_export_change_list_template = "admin/cart/change_list_cart_export.html"
     export_form_class = ExportFormFields
     _cart_session_name = None
     _cart_viewing_name = None
@@ -157,11 +153,9 @@ class CartExportMixin(ExportMixin):
     @csrf_protect_m
     def add_to_cart(self, request, queryset):
         if request.POST.get("select_across", "0") == "0":
-            selected_ids = set(
-                request.POST.getlist(helpers.ACTION_CHECKBOX_NAME, [])
-            )
+            selected_ids = set(request.POST.getlist(helpers.ACTION_CHECKBOX_NAME, []))
         else:
-            selected_ids = set(map(str, queryset.values_list("id", flat=True)))
+            selected_ids = set(map(str, queryset.values_list("pk", flat=True)))
 
         if self._cart_session_name in request.session:
             cart_ids = set(request.session[self._cart_session_name])
@@ -173,18 +167,14 @@ class CartExportMixin(ExportMixin):
         if quant:
             cart_ids.update(selected_ids)
             request.session[self._cart_session_name] = list(cart_ids)
-            self.message_user(
-                request, _("%s itens adicionados no carrinho") % quant
-            )
+            self.message_user(request, _("%s itens adicionados no carrinho") % quant)
         else:
             self.message_user(
                 request, _("Os itens selecionados já estavam no carrinho")
             )
         return HttpResponseRedirect(".")
 
-    add_to_cart.short_description = _(
-        "Armazenar itens no carrinho para exportar"
-    )
+    add_to_cart.short_description = _("Armazenar itens no carrinho para exportar")
 
     @csrf_protect_m
     def remove_from_cart(self, request, queryset):
@@ -195,12 +185,10 @@ class CartExportMixin(ExportMixin):
         if request.POST.get("select_across", "0") == "0":
             remove_ids = set(request.POST.getlist(helpers.ACTION_CHECKBOX_NAME))
         else:
-            remove_ids = set(map(str, queryset.values_list("id", flat=True)))
+            remove_ids = set(map(str, queryset.values_list("pk", flat=True)))
         cart_ids = set(request.session[self._cart_session_name])
 
-        request.session[self._cart_session_name] = list(
-            cart_ids.difference(remove_ids)
-        )
+        request.session[self._cart_session_name] = list(cart_ids.difference(remove_ids))
 
         self.message_user(
             request,
@@ -281,14 +269,10 @@ class CartExportReportMixin(CartExportMixin):
 class ReturnMixin:
     _return_path = None
 
-    def changeform_view(
-        self, request, object_id=None, form_url="", extra_context=None
-    ):
+    def changeform_view(self, request, object_id=None, form_url="", extra_context=None):
         if "_return" in request.GET:
             self._return_path = request.GET.get("_return")
-        return super().changeform_view(
-            request, object_id, form_url, extra_context
-        )
+        return super().changeform_view(request, object_id, form_url, extra_context)
 
     def response_post_save_add(self, request, obj):
         if self._return_path: