Answer 1

itertools.product(*iterables, repeat)
For your example:
import itertools
list(itertools.product([left, right],[shoulder, arm, hand, leg, foot]))

The repeat parameter specifies the amount of times the values in the iterable should repeat in the combination.
e.g list(itertools.product([1,2],repeat=3))
outputs [1,2,1], [1,2,2] etc