In Python 3, they made the / operator do a floating-point division, and added the // operator to do integer division (i.e. quotient without remainder); whereas in Python 2, the / operator was simply integer division, unless one of the operands was already a floating point number.
What is the reason for having '//' in Python?
原文：http://www.cnblogs.com/casperwin/p/6691843.html