minor style fix

[wolnelektury.git] / apps / catalogue / models / book.py

diff --git a/apps/catalogue/models/book.py b/apps/catalogue/models/book.py
index 0438afa..3cab676 100644 (file)
--- a/apps/catalogue/models/book.py
+++ b/apps/catalogue/models/book.py
@@ -391,6 +391,10 @@ class Book(models.Model):
             for child in self.children.all():
                 child.parent_cover_changed()
 
+    def other_versions(self):
+        """Find other versions (i.e. in other languages) of the book."""
+        return type(self).objects.filter(common_slug=self.common_slug).exclude(pk=self.pk)
+
     def related_info(self):
         """Keeps info about related objects (tags, media) in cache field."""
         if self._related_info is not None:
@@ -495,7 +499,7 @@ class Book(models.Model):
         book = self
         rel_info = book.related_info()
         names = [(related_tag_name(tag), Tag.create_url('author', tag['slug']))
-                    for tag in rel_info['tags']['author']]
+                    for tag in rel_info['tags'].get('author', ())]
         if 'parents' in rel_info:
             books = [(name, Book.create_url(slug))
                         for name, slug in rel_info['parents']]