values = {"a":3, "b":2, "c":4}

def product(*args, **kwargs):
    p = 1
    if args:
        for n in args:
            p *= n
    if kwargs:
        for i, j in kwargs:
            p *= j

    return p

product(**values)

-----------------------------------------------------------
for i, j in kwargs:
    ValueError: need more than 1 value to unpack