get all possible n-grams from an iterable

get_ngrams.py

def get_ngrams(iterable):
    length = len(iterable)

    if length == 1:
        yield iterable[0]
        return

    # the 'starting position' loop
    for n in range(length):

        # the 'skip step' loop

        for step in range(1, length):

            # make substrings
            # starting at position 'n' and going up to the length of the string
            for index in range(n, length, step):
                # go from the next character
                index += 1

                # don't emit duplicates
                # (if the step is greater than one
                # and than the length of the would be substring,
                # it's a duplicate)
                if step > 1 and index - n < step:
                    continue
                else:

                    ngram = iterable[n:index:step]
                    yield ngram