:func:`run_length.encode` compresses an iterable with run-length encoding.
It yields groups of repeated items with the count of how many times they
were repeated:
>>> uncompressed = 'abbcccdddd'
>>> list(run_length.encode(uncompressed))
[('a', 1), ('b', 2), ('c', 3), ('d', 4)]
:func:`run_length.decode` decompresses an iterable that was previously
compressed with run-length encoding. It yields the items of the
decompressed iterable:
>>> compressed = [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
>>> list(run_length.decode(compressed))
['a', 'b', 'b', 'c', 'c', 'c', 'd', 'd', 'd', 'd']