It's not specific to Python, it seems to happen in every topic. On a related note, it would be nice to finally see that new posts of the same link would be tied to the other instances (or rejected).
The same URL can't be submitted twice. If you submit a dupe, it just gives a point to the original. Note that for the generator tricks submission, the submitter put a "?" after the URL to get it past the dupe-checker. Other tricks people play are to link to different parts of the site (say, the page containing a presentation instead of the presentation itself).