Disable use of pyc file with no matching py file

[Devin Jeanpierre]

On Tue, Jan 31, 2012 at 6:55 PM, Terry Reedy <tjreedy at udel.edu> wrote:
> Q. "How do I make my old model car do something (it cannot do)?"
> A. "Get the free new model that has that feature added."
>
> Of course, there is a cost to giving up the old and familiar and learning
> and adjusting to the new, even when it is available gratis. A husband
> wearing an old sweater after his wife gives him a new one, and even
> retrieving it from the trash when she tosses it out, is a classic (and true)
> cartoon joke.

It really bothers me that you imagine that there are no other problems
than the newness. It's disheartening, because the problems are not
that trivial and the world would be better if people were less callous
about it, and realized that they exist. Python 3 is not very different
from Python 2, as far as humans are concerned
semantically/syntactically -- but, hell, just pick any project that
uses PyPy, or Jython, or IronPython, or Twisted, or Zope, etc. -- it
can be a lot of effort (sometimes infeasibly much) to port something
dependent on these things, and it's taken years to get the (smallish)
set of dependencies ported that we have now [and we literally paid
people to do it, too!], and still many large projects haven't made the
transition, and many small projects never will.

Anyone that relies on those projects is stuck, and your "free car"
metaphor completely ignores the true cost of wasting that much time
porting everything for a tiny little feature. Evaluating only the
monetary amounts can be misleading as to what the rational decision is
(in particular when there are no monetary amounts). The only true
notion of cost is the alternatives you sacrifice in making a decision:
opportunity cost. The car is not free.

-- Devin