Permutations and Sympy
Investigate if Sympy permutations (http://docs.sympy.org/latest/modules/combinatorics/permutations.html) would be nicer as implementation than our home-rolled solution.
Investigate if Sympy permutations (http://docs.sympy.org/latest/modules/combinatorics/permutations.html) would be nicer as implementation than our home-rolled solution.