refactor: refactor unnecessary else / elif when if block has a return statement (#5735)

The use of `else` or `elif` becomes redundant and can be dropped if the last statement under the leading `if` / `elif` block is a `return` statement.
In the case of an `elif` after `return`, it can be written as a separate `if` block.
For `else` blocks after `return`, the statements can be shifted out of `else`. Please refer to the examples below for reference.

Refactoring the code this way can improve code-readability and make it easier to maintain.

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

InvenTree/stock/api.py

@@ -236,8 +236,7 @@ class StockLocationFilter(rest_filters.FilterSet):
         """Filter by whether or not the location has a location type"""
         if str2bool(value):
             return queryset.exclude(location_type=None)
-        else:
-            return queryset.filter(location_type=None)
+        return queryset.filter(location_type=None)
 
 
 class StockLocationList(APIDownloadMixin, ListCreateAPI):
@@ -483,9 +482,8 @@ class StockFilter(rest_filters.FilterSet):
         if str2bool(value):
             # Filter StockItem with either build allocations or sales order allocations
             return queryset.filter(Q(sales_order_allocations__isnull=False) | Q(allocations__isnull=False))
-        else:
-            # Filter StockItem without build allocations or sales order allocations
-            return queryset.filter(Q(sales_order_allocations__isnull=True) & Q(allocations__isnull=True))
+        # Filter StockItem without build allocations or sales order allocations
+        return queryset.filter(Q(sales_order_allocations__isnull=True) & Q(allocations__isnull=True))
 
     expired = rest_filters.BooleanFilter(label='Expired', method='filter_expired')
 
@@ -496,8 +494,7 @@ class StockFilter(rest_filters.FilterSet):
 
         if str2bool(value):
             return queryset.filter(StockItem.EXPIRED_FILTER)
-        else:
-            return queryset.exclude(StockItem.EXPIRED_FILTER)
+        return queryset.exclude(StockItem.EXPIRED_FILTER)
 
     external = rest_filters.BooleanFilter(label=_('External Location'), method='filter_external')
 
@@ -505,8 +502,7 @@ class StockFilter(rest_filters.FilterSet):
         """Filter by whether or not the stock item is located in an external location"""
         if str2bool(value):
             return queryset.filter(location__external=True)
-        else:
-            return queryset.exclude(location__external=True)
+        return queryset.exclude(location__external=True)
 
     in_stock = rest_filters.BooleanFilter(label='In Stock', method='filter_in_stock')
 
@@ -514,8 +510,7 @@ class StockFilter(rest_filters.FilterSet):
         """Filter by if item is in stock."""
         if str2bool(value):
             return queryset.filter(StockItem.IN_STOCK_FILTER)
-        else:
-            return queryset.exclude(StockItem.IN_STOCK_FILTER)
+        return queryset.exclude(StockItem.IN_STOCK_FILTER)
 
     available = rest_filters.BooleanFilter(label='Available', method='filter_available')
 
@@ -528,9 +523,8 @@ class StockFilter(rest_filters.FilterSet):
             # The 'quantity' field is greater than the calculated 'allocated' field
             # Note that the item must also be "in stock"
             return queryset.filter(StockItem.IN_STOCK_FILTER).filter(Q(quantity__gt=F('allocated')))
-        else:
-            # The 'quantity' field is less than (or equal to) the calculated 'allocated' field
-            return queryset.filter(Q(quantity__lte=F('allocated')))
+        # The 'quantity' field is less than (or equal to) the calculated 'allocated' field
+        return queryset.filter(Q(quantity__lte=F('allocated')))
 
     batch = rest_filters.CharFilter(label="Batch code filter (case insensitive)", lookup_expr='iexact')
 
@@ -552,8 +546,7 @@ class StockFilter(rest_filters.FilterSet):
 
         if str2bool(value):
             return queryset.exclude(q)
-        else:
-            return queryset.filter(q)
+        return queryset.filter(q)
 
     has_batch = rest_filters.BooleanFilter(label='Has batch code', method='filter_has_batch')
 
@@ -563,8 +556,7 @@ class StockFilter(rest_filters.FilterSet):
 
         if str2bool(value):
             return queryset.exclude(q)
-        else:
-            return queryset.filter(q)
+        return queryset.filter(q)
 
     tracked = rest_filters.BooleanFilter(label='Tracked', method='filter_tracked')
 
@@ -580,8 +572,7 @@ class StockFilter(rest_filters.FilterSet):
 
         if str2bool(value):
             return queryset.exclude(q_batch & q_serial)
-        else:
-            return queryset.filter(q_batch & q_serial)
+        return queryset.filter(q_batch & q_serial)
 
     installed = rest_filters.BooleanFilter(label='Installed in other stock item', method='filter_installed')
 
@@ -589,8 +580,7 @@ class StockFilter(rest_filters.FilterSet):
         """Filter stock items by "belongs_to" field being empty."""
         if str2bool(value):
             return queryset.exclude(belongs_to=None)
-        else:
-            return queryset.filter(belongs_to=None)
+        return queryset.filter(belongs_to=None)
 
     has_installed_items = rest_filters.BooleanFilter(label='Has installed items', method='filter_has_installed')
 
@@ -598,8 +588,7 @@ class StockFilter(rest_filters.FilterSet):
         """Filter stock items by "belongs_to" field being empty."""
         if str2bool(value):
             return queryset.filter(installed_items__gt=0)
-        else:
-            return queryset.filter(installed_items=0)
+        return queryset.filter(installed_items=0)
 
     sent_to_customer = rest_filters.BooleanFilter(label='Sent to customer', method='filter_sent_to_customer')
 
@@ -607,8 +596,7 @@ class StockFilter(rest_filters.FilterSet):
         """Filter by sent to customer."""
         if str2bool(value):
             return queryset.exclude(customer=None)
-        else:
-            return queryset.filter(customer=None)
+        return queryset.filter(customer=None)
 
     depleted = rest_filters.BooleanFilter(label='Depleted', method='filter_depleted')
 
@@ -616,8 +604,7 @@ class StockFilter(rest_filters.FilterSet):
         """Filter by depleted items."""
         if str2bool(value):
             return queryset.filter(quantity__lte=0)
-        else:
-            return queryset.exclude(quantity__lte=0)
+        return queryset.exclude(quantity__lte=0)
 
     has_purchase_price = rest_filters.BooleanFilter(label='Has purchase price', method='filter_has_purchase_price')
 
@@ -625,8 +612,7 @@ class StockFilter(rest_filters.FilterSet):
         """Filter by having a purchase price."""
         if str2bool(value):
             return queryset.exclude(purchase_price=None)
-        else:
-            return queryset.filter(purchase_price=None)
+        return queryset.filter(purchase_price=None)
 
     ancestor = rest_filters.ModelChoiceFilter(
         label='Ancestor',
@@ -896,8 +882,7 @@ class StockList(APIDownloadMixin, ListCreateDestroyAPIView):
             return self.get_paginated_response(data)
         elif request.is_ajax():
             return JsonResponse(data, safe=False)
-        else:
-            return Response(data)
+        return Response(data)
 
     def get_queryset(self, *args, **kwargs):
         """Annotate queryset before returning."""
@@ -1359,8 +1344,7 @@ class StockTrackingList(ListAPI):
             return self.get_paginated_response(data)
         if request.is_ajax():
             return JsonResponse(data, safe=False)
-        else:
-            return Response(data)
+        return Response(data)
 
     def create(self, request, *args, **kwargs):
         """Create a new StockItemTracking object.

InvenTree/stock/models.py

@@ -1842,9 +1842,8 @@ class StockItem(InvenTreeBarcodeMixin, InvenTreeNotesMixin, MetadataMixin, commo
             self.delete()
 
             return False
-        else:
-            self.save()
-            return True
+        self.save()
+        return True
 
     @transaction.atomic
     def stocktake(self, count, user, notes=''):
@@ -2234,8 +2233,7 @@ class StockItemTracking(models.Model):
         """Return label."""
         if self.tracking_type in StockHistoryCode.keys():
             return StockHistoryCode.label(self.tracking_type)
-        else:
-            return self.title
+        return self.title
 
     tracking_type = models.IntegerField(
         default=StockHistoryCode.LEGACY,