Sorting python dictionary with tuples of keys and using lambda

Question

Here is how my dictionary looks like:

{((0,), (16,)): 12.0, ((0,), (17,)): 14.0, ((1,), (16,)): 10.0, ((1,), (17,)): 13.0, ((2,), (15,)): 9.0, ((2,), (16,)):