def test_dmp_ground_nth(): assert dmp_ground_nth([[1],[2],[3]], (0,0), 1, ZZ) == 3 assert dmp_ground_nth([[1],[2],[3]], (1,0), 1, ZZ) == 2 assert dmp_ground_nth([[1],[2],[3]], (2,0), 1, ZZ) == 1 assert dmp_ground_nth([[1],[2],[3]], (2,1), 1, ZZ) == 0 assert dmp_ground_nth([[1],[2],[3]], (3,0), 1, ZZ) == 0 raises(IndexError, 'dmp_ground_nth([[3],[4],[5]], (2,-1), 1, ZZ)')
def nth(f, *N): """Returns the `n`-th coefficient of `f`. """ if all(isinstance(n, int) for n in N): return dmp_ground_nth(f.rep, N, f.lev, f.dom) else: raise TypeError("a sequence of integers expected")