Finding groups of increasing numbers in a list

Question

The aim is to find groups of increasing/monotonic numbers given a list of integers. Each item in the resulting group must be of a +1 increment from the previous item

Answer 1

If two consecutive numbers are increasing by one I form a list (group) of tuples of those numbers.

When non-increasing and if the list (group) is non-empty, I unpack it and zip again to rebuild the pair of sequence which were broken by the zip. I use set comprehension to eliminate duplicate numbers.

  def extract_increasing_groups(seq):
    seq = tuple(seq)

    def is_increasing(a,b):
        return a + 1 == b

    def unzip(seq):
        return tuple(sorted({ y for x in zip(*seq) for y in x}))

    group = []
    for a,b in zip(seq[:-1],seq[1:]):
        if is_increasing(a,b):
            group.append((a,b))
        elif group:
            yield unzip(group)
            group = []

    if group:
        yield unzip(group)

if __name__ == '__main__':

    x = [17, 17, 19, 20, 21, 22, 0, 1, 2, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12,

         13, 14, 14, 14, 28, 29, 30, 31, 32, 33, 34, 35, 36, 40]

    for group in extract_increasing_groups(x):
        print(group)

Simpler one using set;

from collections import namedtuple
from itertools import islice, tee

def extract_increasing_groups(iterable):

    iter1, iter2 = tee(iterable)
    iter2 = islice(iter2,1,None)

    is_increasing = lambda a,b: a + 1 == b
    Igroup = namedtuple('Igroup','group, len')

    group = set()
    for pair in zip(iter1, iter2):
        if is_increasing(*pair):
            group.update(pair)
        elif group:
            yield Igroup(tuple(sorted(group)),len(group))
            group = set()

    if group:
        yield Igroup(tuple(sorted(group)), len(group))


if __name__ == '__main__':

    x = [17, 17, 19, 20, 21, 22, 0, 1, 2, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14, 14, 28, 29, 30, 31, 32, 33, 34, 35, 36, 40]
    total = 0
    for group in extract_increasing_groups(x):
        total += group.len
        print('Group: {}\nLength: {}'.format(group.group, group.len))
    print('Total: {}'.format(total))