George Sakkis wrote: > On Feb 17, 7:51 am, Arnaud Delobelle <[EMAIL PROTECTED]> wrote: > >> BTW, I keep using the idiom itertools.chain(*iterable). I guess that >> during function calls *iterable gets expanded to a tuple. Wouldn't it >> be nice to have an equivalent one-argument function that takes an >> iterable of iterables and return the 'flattened' iterable? > > Indeed; I don't have any exact numbers but I roughly use this idiom as > often or more as the case where chain() takes a known fixed number of > arguments. The equivalent function you describe is trivial: > > def chain2(iter_of_iters): > for iterable in iter_of_iters: > for i in iterable: > yield i
or fwiw chainstar = lambda iters : (x for it in iters for x in it) - a form that better suggests how to inline it in the calling expression, if applicable. Cheers, BB -- http://mail.python.org/mailman/listinfo/python-list
