一个测试成功一个测试失败，求解

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#1 Created at ... [Delete] [Delete and Lock User]

def product(numbers): if len(numbers)==0: raise TypeError m=1 for n in numbers: m=mn return m

def product(*numbers):
    if numbers is None:
        raise TypeError
    m=1
    for n in numbers:
        m=m*n
    return m

求大神解释if len(numbers)=0:和if numbers is None:有什么区别？多谢！

#2 Created at ... [Delete] [Delete and Lock User]

None 是一个对象，是一个 NoneType 对象,is None是用来判断是否为None,只有None is None情况下为真,作业里面product()由于参数*number所以输入的是一个空的tuple(). 搞清楚上面的就很好解决了

def product(*numbers):
    if numbers is ():
        raise TypeError
    m=1
    for n in numbers:
        m=m*n
    return m

len(numbers)==0可以理解为空列表[]、空字典{}、空元组()

def product(*numbers):
    if not numbers:
        raise TypeError
    m=1
    for n in numbers:
        m=m*n
    return m

#3 Created at ... [Delete] [Delete and Lock User]

啊明白了~多谢！

#4 Created at ... [Delete] [Delete and Lock User]

厉害了，my bro

#5 Created at ... [Delete] [Delete and Lock User]

很好很强大