[issue1580] Use shorter float repr when possible

[Raymond Hettinger]

Raymond Hettinger <rhettinger at users.sourceforge.net> added the comment:

The advantage is accuracy.  No double rounding.  This will also help the
math.fsum() function that is also susceptible to double rounding.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue1580>
_______________________________________