When playing with the Editline alternative to Readline, I noticed that “global” name completions can include duplicates: >>> No None NotADirectoryError( NotImplementedError( None NotImplemented >>> None None None It completed my line to “None”, but if you hit Tab again, it lists two duplicate options both identical to what I already have. The reason is that “None” is both a reserved keyword, and a member of the builtins module. My patch avoids adding extra completions if a name has already been added. It also prioritizes the global namespace over builtins, so that say if you alias “int” to a non-callable, it is no longer listed with an opening bracket “(” suffix. Earlier behaviour: >>> int = 81 >>> in in input( int int( Now: >>> in in input( int