On Fri, Jun 3, 2016 at 3:17 PM, Neil Schemenauer <nas-pythonideas@arctrix.com> wrote:

I'm nearly finished porting a decently size application from Python
2 to Python 3. It has been a lot of work. I am dubious as to
whether the port was really the best use of time. I can imagine
there is still millions, possibly billions of lines of Python 2 code
that has not yet been converted. Further, my guess is the lines of
Python 2 code are still growing faster than the lines of Python 3
compatible code. IMHO, we need to do better in making it easier for
people to port code.

Here is a thought that occured to me. Create a patched version of
Python 3.x, making a stepping stone version for people porting from
Python 2. I know this would have been useful for me. Specific
changes that would be helpful, all generating warnings so code can
be eventually fixed:

- comparision with None, smaller than all other types

- comparision of distinct types: use Python 2 behavior (i.e. order
by type name)

- mixing of unicode strings with byte strings: decode/encode
using latin-1

To me this sounds more like going back to Python 2 rather than facilitating the transition, especially #3.

Unfortunately there's no middle ground in there: it's either "do this or that" and that's why it's so painful.

Incidentally, all these things you mentioned are bad practices which may hide bugs you may not even be aware of.

The more I think about the porting subject, the more I realize that the difficulty mainly resides in how good your Python 2 code base is. Python 3 attempted to be a better language (mainly) by becoming stricter. As such, a badly written Python 2 code base is harder to port because Python 3 stands in your way acting as a referee for all the mistakes you've made in the past, forcing you to fix them all at once. That's its biggest advantage and damnation at the same time.

Giampaolo - http://grodola.blogspot.com