People who things Python2to3 is was not a big deal are missing the fact that, there was practically no reason to upgrade to python3 until python 3.6, when the d

People who things Python2to3 is was not a big deal are missing the fact that, there was practically no reason to upgrade to python3 until python 3.6, when the dict enhancements were released. The inertia to upgrade can mainly be overcomed, if there are security vulnerability in existing version or you faster performance for free. Other than that, there are very few cases I have seen where upgrading at cost of breaking backwards compatibility makes sense.