split()一下之后用下set去掉多个分割出来的空值排个序就好了吧

while True:
    try:
        x = int(input())
        byte_x = bin(x)[2:]
        list1 = sorted(list(set(byte_x.split('0'))), key = lambda x: len(x), reverse=True)
        print(len(list1[0]))
    except:
        break