Hello,

I’m working on the advanced python code challenge #4 ‘double index’.

I came up with this solution using replace().

```
def double_index(lst, index):
if index >= len(lst):
return lst
else:
return str(lst).replace(str(lst[index]), str(lst[index]*2))
```

This gets the correct result no matter what I give as input to the function. for example, if I enter

`print(double_index([3, 8, -10, 12], 0))`

then I get the result

`[6, 8, -10, 12]`

the number at index 0 is 3. Doubled to give result 6 in the new list.

But the lesson is telling me it’s wrong. Does anybody know why?

Thanks!