From af84a0ee01bfdef599508ad9a29cb3b269992bdf Mon Sep 17 00:00:00 2001
From: Christian Cueni <christian.cueni@iterativ.ch>
Date: Wed, 31 Jul 2024 11:14:19 +0200
Subject: [PATCH] Add return type

---
 server/vbv_lernwelt/dashboard/person_export.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/server/vbv_lernwelt/dashboard/person_export.py b/server/vbv_lernwelt/dashboard/person_export.py
index dacd4272..0a0d76aa 100644
--- a/server/vbv_lernwelt/dashboard/person_export.py
+++ b/server/vbv_lernwelt/dashboard/person_export.py
@@ -1,4 +1,5 @@
 from io import BytesIO
+from typing import Optional
 
 import structlog
 from django.utils.translation import gettext_lazy as _
@@ -22,8 +23,8 @@ def export_persons(
     user: User,
     course_session_ids: list[str],
     save_as_file: bool = False,
-):
-    if len(course_session_ids) == 0:
+) -> Optional[bytes]:
+    if not course_session_ids:
         return
 
     wb = Workbook()