On Sun, 12 Nov 2006 14:56:49 -0600, skip wrote: > > >> Is there a module out there that will generate an image with a random > >> text string such as the confirmation images you see on various > >> websites? > > Mitja> They're called captcha images or captchas for short. Googling > Mitja> for "python captcha" returns several hits; see what you like... > > Thanks. I'd never heard that term before. Assuming I can get PIL installed > with freetype support on my Mac the ASPN recipe looks like it will do the > trick.
Keep in mind two serious problems with captchas: - they're impossible for the blind or people using text-only browsers to see -- even mere colour blindness can make some captchas impossible to solve; - sometimes they're too difficult for even those with perfect vision to decipher. Two alternatives: Instead of displaying an obfuscated image of a nonsense word, display six randomly chosen photos, where five are of the same thing but not the same image. E.g. you might show five different kittens and a horse. The user has to click on the image that is not the same as the others. State-of-the-art horse-recognition software is not yet in widespread use by spammers *wink* For a text only solution, consider putting up a natural language question such as: What is the third letter of 'national'? What is four plus two? How many eggs in a dozen? Fill in the blank: Mary had a little ____ its fleece was white as snow. Cat, Dog, Apple, Bird. One of those words is a fruit. Which one? Beware of making the questions too difficult or too specific: In the third season of Babylon Five, what did Mr Morden ask Lando? Also, keep in mind that all captchas are vulnerable to the old distributed hybrid human-machine network trick: "We'll give you a free account on our porn site if you spend fifteen minutes a day solving captchas for our bot network." The only solution to that, I fear, is open season on spammers and anyone who buys from a spammer. -- Steven. -- http://mail.python.org/mailman/listinfo/python-list
