make sure folder exists

oml/user/models.py

@@ -338,13 +338,14 @@ class List(db.Model):
         pass
 
     def export_json(self, path=None):
+        from utils import _to_json
         if not path:
             if self.name:
                 name = os.path.join('Lists', self.name)
             else:
                 name = 'Books'
             path = os.path.join(os.path.expanduser(settings.preferences['libraryPath']), name, 'library.json')
-        from utils import _to_json
+        ox.makedirs(os.path.dirname(path))
         items = []
         for i in self.get_items():
             j = i.json()