This change stops sleekxmpp from spending huge amounts of time unnecessarily computing logging data that may never be used. This is a HUGE performance improvement; in some of my test runs, unnecessary string creation was accounting for > 60% of all CPU time.

Note that using % in a string will _always_ perform the sting substitutions, because the strings are constructed before the function is called. So log.debug('%s' % expensiveoperation()) will take about the same CPU time whether or not the logging level is DEBUG or INFO. if you use , no substitutions are performed unless the string is actually logged

sleekxmpp/plugins/xep_0050/adhoc.py

@@ -211,8 +211,7 @@ class xep_0050(base_plugin):
         key = (iq['to'].full, node)
         name, handler = self.commands.get(key, ('Not found', None))
         if not handler:
-            log.debug('Command not found: %s, %s' % (key, self.commands))
-
+            log.debug('Command not found: %s, %s' , key, self.commands)
         initial_session = {'id': sessionid,
                            'from': iq['from'],
                            'to': iq['to'],