def cmy_to_cmyk(c, m=None, y=None):
if type(c) in [list,tuple]:<EOL><INDENT>c, m, y = c<EOL><DEDENT>k = min(c, m, y)<EOL>if k==<NUM_LIT:1.0>: return (<NUM_LIT:0.0>, <NUM_LIT:0.0>, <NUM_LIT:0.0>, <NUM_LIT:1.0>)<EOL>mk = <NUM_LIT:1.0>-k<EOL>return ((c-k) / mk, (m-k) / mk, (y-k) / mk, k)<EOL>
Convert the color from CMY coordinates to CMYK.

    Parameters:
      :c:
        The Cyan component value [0...1]
      :m:
        The Magenta component value [0...1]
      :y:
        The Yellow component value [0...1]

    Returns:
      The color as an (c, m, y, k) tuple in the range:
      c[0...1],
      m[0...1],
      y[0...1],
      k[0...1]

    >>> '(%g, %g, %g, %g)' % cmy_to_cmyk(1, 0.66, 0.5)
    '(1, 0.32, 0, 0.5)'