I am unable to produce any results with the following question:

Write a function named

`append_sum`

that has one parameter — a list named named`lst`

. The function should add the last two elements of`lst`

together and append the result to`lst`

. It should do this process three times and then return`lst`

. For example, if`lst`

started as`[1, 1, 2]`

, the final result should be`[1, 1, 2, 3, 5, 8]`

.

Here is my code:

```
#Write your function here
def append_sum(lst):
a = lst[-1] + lst[-2]
lst = lst.append(a)
return lst
#Uncomment the line below when your function is done
print(append_sum([1, 1, 2]))
```

I know I am not producing the results three times here but I would think this would return something. Instead it returns “None”.