> And there's really no upside. Yes there is, the print function is the biggest syntactic incompatibility. Besides the (optional) u marker for unicode strings

> And there's really no upside. Yes there is, the print function is the biggest syntactic incompatibility. Besides the (optional) u marker for unicode strings that they reintroduced later. Most of the other difference (like changed packages) are semantic. You would have been able to import and run Python 2 in Python 3, maybe with a couple of "if"s or some magic in the module loader. Breaking compatibility like this felt petty and deliberate and made it really hard to have one codebase target both python 2 and 3 (temporarily).