Carl Banks wrote: > def process_values(lst): > if not lst: > return > do_expensive_initialization_step() > for item in lst: > do_something_with(item) > do_expensive_finalization_step()
> What if you called the function like this: > > process_values(x.strip() for x in values_lst) > > Oops, now we've just gone through an expensive initialization and > finalization for nothing (since values_lst was empty). Maybe some > subtle bugs introduced. If we're lucky, the finalization step will > throw an exception. The good news is that the above has a 99 percent chance that it just works with iterators/generators -- even though the writer may not have been aware of them/they didn't exist when the code was written... Peter -- http://mail.python.org/mailman/listinfo/python-list
