> Special care is required when specifying rational numbers, because integer division might not produce the answer you want. In other words, Python will not automatically convert the answer to a floating point number, but instead round the answer to the closest integer

Note that this applies only to Python2, Py3k does float-division by default and integer division with // operator:

    Python 2.7.3 (default, Apr 10 2012, 23:31:26) [MSC v.1500 32 bit (Intel)] on win32
    Type "help", "copyright", "credits" or "license" for more information.
    >>> 1/7
    0
    >>> from __future__ import division
    >>> 1/7
    0.14285714285714285
    >>> 1//7
    0
    >>>