migrate update

courses/models.py

@@ -61,6 +61,9 @@ class Topic(models.Model):
     icon = models.ImageField(verbose_name='Иконка темы', null=True, blank=True)
     sort = models.SmallIntegerField(verbose_name='Поле сортировки')
 
+    def __str__(self):
+        return self.title
+
     class Meta:
         verbose_name = "Тема"
         verbose_name_plural = "Темы"