python求最大值

这个是我的代码，运行时候报错，到底是哪里错了呢
def get_max_multiples_of_3(sentence):
sentence = sentence.split("")
list1=[]
for i in sentence:
if abs(int(i)) % 3 ==0:
list1.append(int(i))
list1 = max(list1)
return list1

def get_max_multiples_of_3(sentence):
    sentence = sentence.split(" ")
    list1=[]
    for i in sentence:
        if abs(int(i)) % 3 ==0:
            list1.append(int(i))
    list1 = max(list1)
    return list1
    
print(get_max_multiples_of_3('1 2 3 4 6 0 99 96 0'))

split()括号里不能为空字符串，你这里直接使用split()即可，或者放进去一个空格，split(" ")