On Aug 27, 3:42 pm, George Sakkis <[EMAIL PROTECTED]> wrote: > Below are two more versions that pass all the doctests: the first > works only for lists and modifies them in place and the second works > for arbitrary iterables: > > def clean_inplace(seq, good_ones=4): > start = 0 > n = len(seq) > while start < n: > try: end = seq.index(0, start) > except ValueError: end = n > if end-start >= good_ones: > break > start = end+1 > del seq[:start] > > def clean_iter(iterable, good_ones=4): > from itertools import chain, islice, takewhile, dropwhile > iterator = iter(iterable) > is_zero = float(0).__eq__ > while True: > # consume all zeros up to the next non-zero > iterator = dropwhile(is_zero, iterator) > # take up to `good_ones` non-zeros > good = list(islice(takewhile(bool,iterator), good_ones)) > if not good: # iterator exhausted > return iterator > if len(good) == good_ones: > # found `good_ones` consecutive non-zeros; > # chain them to the rest items and return them > return chain(good, iterator) > > HTH, > George
You gave me an idea-- maybe an arbitrary 'lookahead' iterable could be useful. I haven't seen them that much on the newsgroup, but more than once. IOW a buffered consumer. Something that you could check a fixed number of next elements of. You might implement it as a iterator with a __getitem__ method. Example, unproduced: >>> import itertools >>> a= itertools.count( ) >>> a.next() 0 >>> a.next() 1 >>> a[ 3 ] 5 >>> a.next() 2 >>> a[ 3 ] 6 Does this make sense at all? -- http://mail.python.org/mailman/listinfo/python-list
