fix image save for old Python versions (#390)

netbox_topology_views/api/views.py

@@ -1,4 +1,5 @@
 from typing import Dict
+import sys
 
 from circuits.models import Circuit
 from dcim.models import Device, DeviceRole, PowerFeed, PowerPanel
@@ -149,6 +150,7 @@ class SaveRoleImageViewSet(PermissionRequiredMixin, ReadOnlyModelViewSet):
                 {"status": "Missing or malformed request body"}, status=400
             )
 
+        if sys.version_info >= (3,9,0):
             device_roles = {
                 k: v.removeprefix(settings.STATIC_URL)
                 for k, v in request.data.items()
@@ -158,6 +160,16 @@ class SaveRoleImageViewSet(PermissionRequiredMixin, ReadOnlyModelViewSet):
                 for k, v in request.data.items()
                 if k.startswith("ct") and k[2:].isnumeric()
             }
+        else:
+            device_roles = {}
+            for k, v in request.data.items():
+                if k.isdigit() and v.startswith(settings.STATIC_URL):
+                    device_roles[k] = v[len(settings.STATIC_URL):]
+
+            content_type_ids = {}
+            for k, v in request.data.items():
+                if k.startswith("ct") and k[2:].isdigit() and v.startswith(settings.STATIC_URL):
+                    content_type_ids[k[2:]] = v[len(settings.STATIC_URL):]
 
         roles: Dict[int, DeviceRole] = DeviceRole.objects.in_bulk(device_roles.keys())
         content_types: Dict[int, ContentType] = ContentType.objects.in_bulk(