[Python-Dev] Other library code transformations

[Guido van Rossum]

> Certainly distinguishing between Required changes and Recommended
> changes would be a good thing. Required changes are what needs to be
> done to keep old code working. Recommended changes could include
> stylistic changes, new features, new idioms, etc. I think it would
> even make sense to talk about changes that should be made in
> anticipation of future feature deprecation.

I'm not sure that using x+=1 instead of x=x+1 should be even a
recommended change.  This is a personal choice, just like using
True/False to indicate truth values.

The "is None" vs. "== None" issue is a general style recommendation,
not a migration tip.  This is a "should do" issue.

The "if not x" vs. "if x is None" issue is also a general style
recommendation.  This is a "could do" issue, because the semantics are
different.

--Guido van Rossum (home page: http://www.python.org/~guido/)