jb wrote: > I have two lists, x and y with the property len(x) = len(y). > > I should like to achive this (x is a list of class instances) > > for (a,b) in (x,y): a.f(b) no doubt, you get hundreds of suggestions. pythoneers *love* these kind of tasks :-) for (a,b) in zip(x,y): a.f(b) would be the most straigtforward, i guess. holger