colorsys.rgb_to_hsv appears to be broken on python2.7.13 (on archlinux).
Saturation is always reported as 0.

ex:

import colorsys
rgb_to_hsv( 127, 116, 18 )
>>> (0.16666666666666666, 0, 127)

The bug appears to be caused by the difference in division
symbols between python3 vs python2.

The issue appears to be resolved if you add the following line to the
`/usr/lib/python2.7.13/colorsys.py` module (or if all arguments are converted to floats).

from __future__ import division

I noticed that this bug persists all the back to at least python2.7.10

The arguments to rgb_to_hsv are supposed to be floating-point numbers in the range 0.0 to 1.0. That's documented here: https://docs.python.org/2/library/colorsys.html

> Coordinates in all of these color spaces are floating point values. In the YIQ space, the Y coordinate is between 0 and 1, but the I and Q coordinates can be positive or negative. In all other spaces, the coordinates are all between 0 and 1.

oh, thank you very much and sorry for my negligence!

No problem. I did spend some time wondering whether `rgb_to_hsv` still gives the correct results if any of the inputs happens to be an integer (though still in the range [0, 1]). It looks as though it does, though.