[Python-Dev] PEP 460: allowing %d and %f and mojibake

[Stephen J. Turnbull]

Greg Ewing writes:

 > I don't think of my viewpoint as being PBP. That term
 > assumes there is purity there to be beaten. To my mind,
 > any notion of purity with respect to bytes objects
 > went out the window as soon as it was given a pile
 > of text methods -- together with a text-like literal
 > syntax and default repr(), even though at least half
 > the time they're completely inappropriate!

Isn't an analogous statement true of every programming language taken
as a whole?  Does that mean that, because Python 1 text handling was
unavoidably "practical", adding the "purist" unicode type in Python 2
was a mistake?  Python 3's sacrifice of Python 2 compatibility seems
positively degenerate by your standard!

To be less contentious, surely the concept of "purity" includes
"purification" (even if that doesn't apply to some subdivisions of
purity)?

In any case, taking your statement at face value, I consider adding
the methods to have been a mistake and the literal syntax and repr to
be compact abbreviations that are frequently convenient.

Byte sequences that can be considered to serializations of objects
including ASCII text, so that some subsequences of bytes in the range
0-127 can be usefully considered as a text representation are very
common.  But I think that they're important enough that their
representation in Python deserves a type (maybe more than one) that
tries to enforce what regularities there are in such streams.

The purity position is probably going to lose in the end, since Guido
is clearly in the PBP camp at this point, and that's a strong
indicator (especially since Nick has given up on convincing
python-dev).  But that does not mean it's entirely invalid.