solution.py

#!/usr/bin/python3
import logging

def rle(iterable):
    _next = next
    it = iter(iterable)
    value, count = None, 0
    try:
        while True:
            item = _next(it)
            if item == value:
                count += 1
            else:
                if count > 0:
                    yield count, value
                value = item
                count = 1
    except StopIteration:
        if count > 0:
            yield count, value

# number_to_string = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9']

def look_and_say(num):
    # save ~100ms
    # _nt = number_to_string
    for c, v in rle(num):
        # yield _nt[c]
        yield c
        yield v


if __name__ == '__main__':
    logging.basicConfig(format='[+%(relativeCreated)d ms] %(levelname)s %(message)s', level=logging.INFO)

    start = map(int, '1113222113')

    for _ in range(50):
        start = look_and_say(start)
        logging.info("Iteration #{}".format(_))
    logging.info('Solution: {}'.format(sum(1 for _ in start)))