Understanding how is a function evaluated using recursion

[Josh English]

On Wednesday, September 25, 2013 4:24:22 PM UTC-7, Arturo B wrote:
> Hi, I'm doing Python exercises and I need to write a function to flat nested lists


> So I know what recursion is, but I don't know how is 
>
>                        flatten(i)
>  
> evaluated, what value does it returns?
> 

In this case, flatten always returns a list. When it hits the recursion, it calls itself to get another list, that it uses to extend the current list.

Josh