def product(num,*args):

    for i in args:

    num*=i

    return num

print('product(5) =', product(5))

print('product(5, 6) =', product(5, 6))

print('product(5, 6, 7) =', product(5, 6, 7))

print('product(5, 6, 7, 9) =', product(5, 6, 7, 9))

if product(5) != 5:

    print('测试失败!')

elif product(5, 6) != 30:

    print('测试失败!')

elif product(5, 6, 7) != 210:

    print('测试失败!')

elif product(5, 6, 7, 9) != 1890:

    print('测试失败!')

else:

    try:

        product()

        print('测试失败!')

    except TypeError:

        print('测试成功!')