sympy/sympy — pull request #1680 by smichr (2012-11-30 09:20:16+00:00)
Title: 2950: Rational accepts only rational-like input

Refuse the temptation to guess: insist on integer input. See the
issue page for discussion.

http://code.google.com/p/sympy/issues/detail?id=2950

This also brought to attention the use of / when // should have
been used.

There are also commits here which clean up numbers.py a bit
and restore the Float(0) -> S.Zero behavior while still allowing
Float(nonzeroint) -> Float.