def get_list(st):
    ls=[]
    for i in range(0,len(st)):
        for j in range(i+1,len(st)):
            ls.append(st[i:j])
    print(ls)
    return ls

data=get_list('abcdegabcdi')
def repeat_list():
    repeat=[]
    for l in range(0,len(data)):
        for m in range(l+1,len(data)):
            if data[l]==data[m]:
                repeat.append(data[l])
    print(repeat)
    return repeat

repeat_list=repeat_list()
rl=list(set(repeat_list))

maxl=1
dict={}
for I in range(0,len(rl)):
    dict.update({len(rl[I]):rl[I]})
    if len(rl[I])>maxl:
        maxl=len(rl[I])
print('最大長度是：',maxl)
print('最大重複元素是:',dict[maxl])