Steve Holden <[EMAIL PROTECTED]> wrote: > [EMAIL PROTECTED] wrote: > > Laurent Pointal: > >> you may prefer range/items when processing of the result > >> value explicitly need a list (ex. calculate its length) > > > > Creating a very long list just to know the len of an iterator is > > barbaric, so sometimes I use this: > > > > def leniter(iterator): > > if hasattr(iterator, "__len__"): > > return len(iterator) > > nelements = 0 > > for _ in iterator: > > nelements += 1 > > return nelements > > > Of course this is a little like the Heisenberg uncertainty principle if > the iterator has no __len__ attribute - once you know how long it is you > no longer have access to the elements. Or did I miss something?
Right. However, "return sum(1 for _ in iterator)" may be a handier way to express the same desctructive semantics as the last 4 lines here. Alex -- http://mail.python.org/mailman/listinfo/python-list
