format_html formatting

fet2020/finance/admin.py

@@ -329,7 +329,7 @@ class BillAdmin(admin.ModelAdmin):
             return "Daten für QR Code ungültig"
 
         uri = qrcode.png_data_uri(scale=3.0)
-        return format_html(f'<img src="{uri}">')
+        return format_html('<img src="{}">', uri)
 
     @admin.display(description="Status")
     def status_colored(self, obj):
@@ -341,7 +341,9 @@ class BillAdmin(admin.ModelAdmin):
             Bill.Status.INCOMPLETED: "blue",
         }
         return format_html(
-            f'<b style="background:{colors[obj.status]};">{obj.get_status_display()}</b>'
+            '<b style="background:{color};">{status}</b>',
+            color=colors[obj.status],
+            status=obj.get_status_display(),
         )
 
     @admin.action(description="Als 'Abgerechnet' markieren.")
@@ -463,7 +465,7 @@ class ResolutionAdmin(admin.ModelAdmin):
 
         if fetmeeting is not None:
             link = f"https://{settings.HOST_NAME}/posts/{fetmeeting.slug}/"
-            return format_html(f"<a href='{link}' target='_blank'>Link zur Fachschaftssitzung</a>")
+            return format_html('<a href="{}" target="_blank">Link zur Fachschaftssitzung</a>', link)
 
         return format_html("-")