./python.exe -m timeit -s 'from fractions import Fraction' 'Fraction(3)`
31.7 usec/loop -> 9.2 usec/loop

  ./python.exe -m timeit -s 'from fractions import Fraction' 'Fraction(3, 2)'`
27.7 usec/loop -> 9.32 usec/loop

  ./python.exe -m timeit -s 'from fractions import Fraction; f = Fraction(3, 2)' 'Fraction(f)'
31.9 usec/loop -> 14.3 usec/loop

test_fractions.py.  This should have been part of the name
change from Rational to Fraction.

Remove Fraction.to_continued_fraction and
Fraction.from_continued_fraction

Fraction(1, 2) instead of Fraction(1,2).

with numbers.Rational.  See issue #1682 for related discussion.

instances.

http://mail.python.org/pipermail/python-dev/2008-January/076626.html and issue
1965.

this patch to py3k.

Raymond's advice.

Add first-cut at an approximation function (still needs rounding tweaks).  Add continued fraction conversions.

__init__ to __new__ to enforce immutability, and remove "rational." from repr
and the parens from str.

precision. This has been discussed at http://bugs.python.org/issue1682. It's
useful primarily for teaching, but it also demonstrates how to implement a
member of the numeric tower, including fallbacks for mixed-mode arithmetic.

I expect to write a couple more patches in this area:
 * Rational.from_decimal()
 * Rational.trim/approximate() (maybe with different names)
 * Maybe remove the parentheses from Rational.__str__()
 * Maybe rename one of the Rational classes
 * Maybe make Rational('3/2') work.