Fix circular import in serializers

Move imports to module level in segment and segment_financial_info
serializers to avoid circular import issues.

Author: Kani999

cesnet_service_path_plugin/api/serializers/segment.py

@@ -10,6 +10,9 @@
 from netbox.api.serializers import NetBoxModelSerializer
 from rest_framework import serializers
 
+from cesnet_service_path_plugin.api.serializers.segment_financial_info import (
+    SegmentFinancialInfoSerializer,
+)
 from cesnet_service_path_plugin.models.segment import Segment
 from cesnet_service_path_plugin.utils import (
     determine_file_format_from_extension,
@@ -93,9 +96,6 @@ def get_financial_info(self, obj):
         request = self.context.get("request")
         if not request:
             return None
-        from cesnet_service_path_plugin.api.serializers.segment_financial_info import (
-            SegmentFinancialInfoSerializer,
-        )
 
         # Check if user has permission to view financial info
         has_financial_view_perm = request.user.has_perm("cesnet_service_path_plugin.view_segmentfinancialinfo")

cesnet_service_path_plugin/api/serializers/segment_financial_info.py

@@ -1,8 +1,8 @@
 # cesnet_service_path_plugin/api/serializers/segment_financial_info.py
-from rest_framework import serializers
 from netbox.api.serializers import NetBoxModelSerializer
+from rest_framework import serializers
 
-from cesnet_service_path_plugin.models import SegmentFinancialInfo
+from cesnet_service_path_plugin.models import Segment, SegmentFinancialInfo
 
 
 class SegmentPrimaryKeyRelatedField(serializers.PrimaryKeyRelatedField):
@@ -11,8 +11,6 @@ class SegmentPrimaryKeyRelatedField(serializers.PrimaryKeyRelatedField):
     """
 
     def get_queryset(self):
-        from cesnet_service_path_plugin.models import Segment
-
         return Segment.objects.all()