recursion gotcha?

[Marco Bizzarri]

On Sun, Sep 14, 2008 at 10:01 AM, cnb <circularfunc at yahoo.se> wrote:
> this recursive definition of sum thrumped me, is this some sort of
> gotcha or am I just braindead today?
> and yes i know this is easy a a for x in xs acc += x or just using the
> builtin.
>
> def suma(xs, acc=0):
>        if len(xs) == 0:
>                acc
>        else:
>                suma(xs[1:], acc+xs[0])

You're just missing the "return" statements?

def suma(xs, acc=0):
       if len(xs) == 0:
              return acc
       else:
              return suma(xs[1:], acc+xs[0])


Regards
Marco
-- 
Marco Bizzarri
http://notenotturne.blogspot.com/
http://iliveinpisa.blogspot.com/