[issue1580] Use shorter float repr when possible

[Raymond Hettinger]

Raymond Hettinger added the comment:

Right, there are plenty of exceptions to the suggestion of exactness. 
Still, I find the current behavior to be more helpful than not 
(especially when trying to explain the examples I gave in the previous 
post).

I'm concerned that the tone of the recent discussion shows a strong 
desire to just get something checked-in despite dubious benefits and 
despite long standing invariants.

It is a bit cavalier to declare "we can give up float(repr(x)) == x 
across different platforms."  Our NumPy friends might not be amused. If 
a PEP on this were circulated, I'm sure we would receive some frank and 
specific feedback.

Likewise, I find it questionable that shorter reprs are helpful. Is 
there any evidence supporting that assertion?  My arguments above 
suggest short reprs are counter-productive because they mask the cause 
of problems that might otherwise be self-evident.  Of course, it's 
possible that both could be true, short reprs may help in some cases 
(by masking oddities) and may hurt in other cases (by masking the 
underlying cause of an oddity or by making a false psychological 
suggestion).

__________________________________
Tracker <report at bugs.python.org>
<http://bugs.python.org/issue1580>
__________________________________