Simple recursive sum function | what's the cause of the weird behaviour?

[Rotwang]

On 06/07/2013 21:10, Rotwang wrote:
> [...]
>
> It's not quite clear to me what the OP's intentions are in the general
> case, but calling supersum(item, start) seems odd - for example, is the
> following desirable?
>
>  >>> supersum([[1], [2], [3]], 4)
> 22
>
> I would have thought that the "correct" answer would be 10. How about
> the following?
>
> def supersum(sequence, start = 0):
>      result = start
>      for item in reversed(sequence):
>          try:
>              result = supersum(item, result)
>          except:
>              result = item + result
>      return result

Sorry, I've no idea what I was thinking with that reversed thing. The 
following seems better:

def supersum(sequence, start = 0):
     result = start
     for item in sequence:
         try:
             result = supersum(item, result)
         except:
             result = result + item
     return result