In article <[EMAIL PROTECTED]>, Ben Finney <[EMAIL PROTECTED]> wrote: > >Fourth, if you have decided that a magic sentinel value is called for >but None is already taken for some other purpose, don't use a >string. Use a unique do-nothing object, defined at the module level so >callers can easily get at it, like 'Dmitry Vasiliev' showed >[reproduced below]. > > GLOBAL = object() > > def insert_ids(ids=GLOBAL): > if ids is GLOBAL: > ids = get_global_ids()
The one disadvantage of this approach is that it complicates pickling if/when you store the stentinel in an instance. There are ways of working around that, but none are pleasant. -- Aahz ([EMAIL PROTECTED]) <*> http://www.pythoncraft.com/ "If you don't know what your program is supposed to do, you'd better not start writing it." --Dijkstra -- http://mail.python.org/mailman/listinfo/python-list
