Fix saving Course model

apps/course/models.py

@@ -75,9 +75,15 @@ class Course(models.Model):
     update_at = models.DateTimeField(auto_now=True)
 
     def save(self, *args, **kwargs):
-        print(self.title)
-        self.slug = slugify(self.title[:100] + '_' + str(uuid4())[:6], allow_unicode=True)
-        print(self.slug)
+        if not self.slug:
+            self.slug = slugify(
+                self.title[:100],
+                allow_unicode=True
+            )
+
+        if Course.objects.filter(slug=self.slug).exists():
+            self.slug += '_' + str(uuid4())[:6]
+
         return super().save()
 
     @property