+def update_counters():
+ for author in Author.select():
+ author.count = len(author.books)
+
+ for ext in Extension.select():
+ ext.count = Book.select(Book.q.extension == ext.name).count()
+
+ for genre in Genre.select():
+ genre.count = len(genre.books)
+
+ for language in Language.select():
+ language.count = Book.select(Book.q.language == language.name).count()
+
+