--- a/etherlab/etherlab.py	Sat Sep 29 13:34:06 2018 +0300
+++ b/etherlab/etherlab.py	Sat Sep 29 13:44:02 2018 +0300
@@ -241,7 +241,7 @@
                     for device in self.devices_xpath(self.modules_infos):
                         device_group = device.getGroupType()
                         if device_group not in vendor_category["groups"]:
-                            raise ValueError, "Not such group \"%\"" % device_group
+                            raise ValueError("Not such group \"%\"" % device_group)
                         vendor_category["groups"][device_group]["devices"].append(
                             (device.getType().getcontent(), device))