python - 在列表中插入特定索引处的元素，覆盖相同索引处的元素或扩展列表

Question

我有一个如下所示的列表:

a_list = ['A','B','C','D']

我想实现类似的目标(能够扩展列表):

new_index = 6
new_value = 'AA'
a_list = insert_value(new_index, new_value)
print(a_list)
#['A','B','C','D','','','AA']

还有类似的东西(能够覆盖 new_value):

new_index = 2
new_value = 'AA'
a_list = insert_value(new_index, new_value)
print(a_list)
#['A','B','AA','D']

Answer 1

我认为你需要:

def expand_insert(lst, idx, ele):
    if len(lst) < idx:
        void = idx - len(lst)

        for i in range(void):
            lst.append("")
        lst.append(ele)
    else:
        lst[idx] = ele
    return lst

print(expand_insert(a_list, 6, "AA"))