En Mon, 28 May 2007 05:25:18 -0300, Maric Michaud <[EMAIL PROTECTED]> escribió:
> Gabriel Genellina a écrit : >> - iterate backwards: >> >> for i in range(len(names)-1, -1, -1): >> fname = names[i] >> if fname[:1]=='.': >> names.remove(fname) >> > > This is not about iterating backward, this is about iterating over the > index of each element instead of iterating over the element (which must > be done begining by the end). In fact this code is both inefficient and > contains a subtle bug. If two objects compare equals in the list, you > will remove the wrong one. > > It should be : > > for i in range(len(names)-1, -1, -1): > if names[i][:1]=='.': > del names[i] Yes, sure, this is what I should have written. Thanks for the correction! >> - filter and reassign in place > > Seems the best here. > >> (the [:] is important): > > Not so. Unless "names" is referenced in another namespace, simple > assignment is enough. But this is exactly the case; the visit function is called from inside the os.path.walk code, and you have to modify the names parameter in-place for the caller to notice it (and skip the undesided files and folders). -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
