Python needs a benevolent dictator ;-)

I'd be happy for Mark, Raymond, or me to play that role here.  If it were me, I'd drop the k <= n requirement:  both arguments must be non-negative integers.  Because a combinatorial (not factorial-, and certainly not gamma-, based) definition of `comb()` is best suited for Python's general audience, and "number of ways to pick k things out of n without regard to order" makes clear sense for any pair of non-negative k and n.  But anything beyond that does not.