ef mul(a, *args):
	for n in args:
		a=a*n
	return a

print('mul(5) =', mul(5))
print('mul(5, 6) =', mul(5, 6))
print('mul(5, 6, 7) =', mul(5, 6, 7))
print('mul(5, 6, 7, 9) =', mul(5, 6, 7, 9))
if mul(5) != 5:
    print('测试失败!')
elif mul(5, 6) != 30:
    print('测试失败!')
elif mul(5, 6, 7) != 210:
    print('测试失败!')
elif mul(5, 6, 7, 9) != 1890:
    print('测试失败!')
else:
    try:
        mul()
        print('测试失败!')
    except TypeError:
        print('测试成功!')