Python from Wise Guy's Viewpoint

[Alex Martelli]

Frode Vatvedt Fjeld wrote:
   ...
>> excessive overhead, in Python we like to MEASURE performance issues
>> rather than just reason about them "abstractly"; which is why Python
>> comes with a handy timeit.py script to time a code snippet
>> accurately. [...]
> 
> Thank you for the detailed information. Still, I'm sure you will agree
> that sometimes reasoning about things can provide insight with
> predictive powers that you cannot achieve by mere experimentation.

A few centuries ago, a compatriot of mine was threatened with
torture, and backed off, because he had dared state that "all
science comes from experience" -- he refuted the "reasoning
about things" by MEASURING (and fudging the numbers, if the
chi square tests about his reports about the sloping-plane
experiments are right -- but then, Italians _are_ notoriously
untrustworthy, even though sometimes geniuses;-).

These days, I'd hope not to be threatened with torture if I assert:
"reasoning" is cheap, that's its advantage -- it can lead you to
advance predictive hypotheses much faster than mere "data
mining" through masses of data might yield them.  But those
hypotheses are very dubious until you've MEASURED what they
predict.  If you don't (or can't) measure, you don't _really KNOW_;
you just _OPINE_ (reasonably or not, justifiably or not, etc).  One
independently repeatable measurement trumps a thousand clever
reasonings, when that measurement gives numbers contradicting
the reasonings' predictions -- that one number sends you back to
the drawing board.

Or, at least, that's how we humble engineers see the world...


Alex