The implicit coercion between bytes and unicode was one of the biggest hurtles I ran into when porting a relatively large (30k+ lines) code base from Python 2 to 3. Also challenging was the change in comparisons (None no longer smaller than all types, TypeError when trying to order disjoint types). While this looks like an interesting hack, I can't see anyone seriously using it to backport code to Python 2.7.

As I mentioned elsewhere, I created "ppython" to handle these two porting problems. The source code is on github: https://github.com/nascheme/ppython . If someone needs a Windows binary, I could build it if you ask politely. ;-) For my project, it has been a useful tool to speed up porting.

Porting code is not trivial and there is huge amount of Python 2 out there. I wish more effort had been spent building tools to help porting of code. Even simple things like disallowing the 'u' prefix on strings in Python 3 was a big mistake. Mostly those things have been corrected but it is still going to take a very long time to move the majority of the community to Python 3. There will be Python 2 running for the next 50 years easily, I'm sure, maybe 100 years. At least Python is open source and you will not be stranded like VB developers where when MS drastically changed Visual Basic.