def diffvalues(t1, t2, f):

    t1v = set(values(t1, f))
    t2v = set(values(t2, f))
    return t2v - t1v, t1v - t2v
Return the difference between the values under the given field in the two
dataset/ETHPy150Open alimanfoo/petl/petl/util/misc.py/diffvalues