Because I'm in school and I fancy cake !

i_like_cake.py

"""
TODO: Example:
I have 5 instances but 12 partitions
I want all instances to consume so one instance must consume on an odd number
"""
import math


def get_chunks(iterable, parts):
    """Yield successive chunks from ``len(iterable) / parts``.

    Arguments:
        iterable (``list``): The list to operate on
        parts (``int``): The amount of chunks to yield

    Yields:
        ``list``
    """
    result = []
    extras = len(iterable) % parts  # The python modulo function is your friend ;)
    added_last_time = False
    items_pr_part = math.floor(len(iterable)/parts)

    for i in iterable:
        result.append(i)
        if len(result) >= items_pr_part:
            if extras and not added_last_time:
                extras -= 1
                added_last_time = True
                continue
            yield result
            added_last_time = False
            del result[:]
    if result:
        yield result

def test_get_chunks():
    partitions = ['3', '2', '10', '1', '0', '7', '6', '5', '4', '9', '8', '11', '14', '20', '23', '90', '11', '34', '83', '92', '182']
    instances = ['i-31dab9d7', 'i-900f6274', 'i-950f6271', 'i-b6b7d251',
                 'i-b7b7d250',]
    chunks = list(get_chunks(partitions, len(instances)))
    assert len(chunks) == len(instances)


if __name__ == '__main__':
    test_get_chunks()