recursion depth problem

[proctor]

On Apr 22, 1:24 pm, Michael Bentley <mich... at jedimindworks.com> wrote:
> On Apr 22, 2007, at 1:49 PM, proctor wrote:
>
>
>
> > i have a small function which mimics binary counting.  it runs fine as
> > long as the input is not too long, but if i give it input longer than
> > 8 characters it gives
>
> > RuntimeError: maximum recursion depth exceeded in cmp
>
> > i'm not too sure what i am doing improperly.  is there really a lot of
> > recursion in this code?
>
> > ==================
>
> > import sys
>
> > def ch4(item, n=0):
> >    if n < len(item):
> >            if item[n] == '0':
> >                    item[n] = '1'
> >                    print ''.join(item)
> >                    ch4(item)
> >            elif item[n] == '1':
> >                    item[n] = '0'
> >                    ch4(item, n+1)
>
> > ch4(list(sys.argv[1]))
>
> > ==================
>
> Yes.  There really is *that* much recursion in that code.  502 levels
> with input length of 8 characters, 1013 with 9 characters, 2035 with
> 10 characters...  There's a pattern there ;-)

ok, thanks michael!

is there a way to avoid it here?  how could i write this better, (if
at all)?

proctor.