Human validation with an image

[Anton Vredegoor]

Peter Hansen <peter at engcorp.com> wrote:

>Other options?  Or pointers to the right keywords to let someone 
>investigate the state of the art/literature more closely?

One idea might be to ask the user to answer a specific computing
intensive question, for example solving a randomly generated traveling
salesman problem of a suitable size. The idea behind this is that a
spammer wants to send thousands of messages and can't afford to
compute the answer to these questions thousands of times, while a
single user can afford to let his computer chew on a problem for a few
seconds.

I would be interested in a Python implementation of this mail
validation scheme.

Anton