Iterate through a list or tuple, allowing each element to be a subset of the sequence.
def slice_sequence(sequence, limit):
"""
Return subsets of sequence, each no larger than limit.
"""
end = 0
maxsize = len(sequence)
while True:
start = end
end = limit + end
end = end if end < maxsize else maxsize
yield sequence[start: end]
if end == maxsize:
break