Lib/test/test_colorsys.py

   1 import unittest, test.test_support
   2 import colorsys
   3
   4 def frange(start, stop, step):
   5     while start <= stop:
   6         yield start
   7         start += step
   8
   9 class ColorsysTest(unittest.TestCase):
  10
  11     def assertTripleEqual(self, tr1, tr2):
  12         self.assertEqual(len(tr1), 3)
  13         self.assertEqual(len(tr2), 3)
  14         self.assertAlmostEqual(tr1[0], tr2[0])
  15         self.assertAlmostEqual(tr1[1], tr2[1])
  16         self.assertAlmostEqual(tr1[2], tr2[2])
  17
  18     def test_hsv_roundtrip(self):
  19         for r in frange(0.0, 1.0, 0.2):
  20             for g in frange(0.0, 1.0, 0.2):
  21                 for b in frange(0.0, 1.0, 0.2):
  22                     rgb = (r, g, b)
  23                     self.assertTripleEqual(
  24                         rgb,
  25                         colorsys.hsv_to_rgb(*colorsys.rgb_to_hsv(*rgb))
  26                     )
  27
  28     def test_hsv_values(self):
  29         values = [
  30             # rgb, hsv
  31             ((0.0, 0.0, 0.0), (  0  , 0.0, 0.0)), # black
  32             ((0.0, 0.0, 1.0), (4./6., 1.0, 1.0)), # blue
  33             ((0.0, 1.0, 0.0), (2./6., 1.0, 1.0)), # green
  34             ((0.0, 1.0, 1.0), (3./6., 1.0, 1.0)), # cyan
  35             ((1.0, 0.0, 0.0), (  0  , 1.0, 1.0)), # red
  36             ((1.0, 0.0, 1.0), (5./6., 1.0, 1.0)), # purple
  37             ((1.0, 1.0, 0.0), (1./6., 1.0, 1.0)), # yellow
  38             ((1.0, 1.0, 1.0), (  0  , 0.0, 1.0)), # white
  39             ((0.5, 0.5, 0.5), (  0  , 0.0, 0.5)), # grey
  40         ]
  41         for (rgb, hsv) in values:
  42             self.assertTripleEqual(hsv, colorsys.rgb_to_hsv(*rgb))
  43             self.assertTripleEqual(rgb, colorsys.hsv_to_rgb(*hsv))
  44
  45     def test_hls_roundtrip(self):
  46         for r in frange(0.0, 1.0, 0.2):
  47             for g in frange(0.0, 1.0, 0.2):
  48                 for b in frange(0.0, 1.0, 0.2):
  49                     rgb = (r, g, b)
  50                     self.assertTripleEqual(
  51                         rgb,
  52                         colorsys.hls_to_rgb(*colorsys.rgb_to_hls(*rgb))
  53                     )
  54
  55     def test_hls_values(self):
  56         values = [
  57             # rgb, hls
  58             ((0.0, 0.0, 0.0), (  0  , 0.0, 0.0)), # black
  59             ((0.0, 0.0, 1.0), (4./6., 0.5, 1.0)), # blue
  60             ((0.0, 1.0, 0.0), (2./6., 0.5, 1.0)), # green
  61             ((0.0, 1.0, 1.0), (3./6., 0.5, 1.0)), # cyan
  62             ((1.0, 0.0, 0.0), (  0  , 0.5, 1.0)), # red
  63             ((1.0, 0.0, 1.0), (5./6., 0.5, 1.0)), # purple
  64             ((1.0, 1.0, 0.0), (1./6., 0.5, 1.0)), # yellow
  65             ((1.0, 1.0, 1.0), (  0  , 1.0, 0.0)), # white
  66             ((0.5, 0.5, 0.5), (  0  , 0.5, 0.0)), # grey
  67         ]
  68         for (rgb, hls) in values:
  69             self.assertTripleEqual(hls, colorsys.rgb_to_hls(*rgb))
  70             self.assertTripleEqual(rgb, colorsys.hls_to_rgb(*hls))
  71
  72 def test_main():
  73     test.test_support.run_unittest(ColorsysTest)
  74
  75 if __name__ == "__main__":
  76     test_main()