from fractions import Fraction from PIL import Image, TiffImagePlugin from PIL.TiffImagePlugin import IFDRational from .helper import PillowTestCase, hopper class Test_IFDRational(PillowTestCase): def _test_equal(self, num, denom, target): t = IFDRational(num, denom) self.assertEqual(target, t) self.assertEqual(t, target) def test_sanity(self): self._test_equal(1, 1, 1) self._test_equal(1, 1, Fraction(1, 1)) self._test_equal(2, 2, 1) self._test_equal(1.0, 1, Fraction(1, 1)) self._test_equal(Fraction(1, 1), 1, Fraction(1, 1)) self._test_equal(IFDRational(1, 1), 1, 1) self._test_equal(1, 2, Fraction(1, 2)) self._test_equal(1, 2, IFDRational(1, 2)) def test_nonetype(self): # Fails if the _delegate function doesn't return a valid function xres = IFDRational(72) yres = IFDRational(72) self.assertIsNotNone(xres._val) self.assertIsNotNone(xres.numerator) self.assertIsNotNone(xres.denominator) self.assertIsNotNone(yres._val) self.assertTrue(xres and 1) self.assertTrue(xres and yres) def test_ifd_rational_save(self): methods = (True, False) if "libtiff_encoder" not in dir(Image.core): methods = (False,) for libtiff in methods: TiffImagePlugin.WRITE_LIBTIFF = libtiff im = hopper() out = self.tempfile("temp.tiff") res = IFDRational(301, 1) im.save(out, dpi=(res, res), compression="raw") reloaded = Image.open(out) self.assertEqual(float(IFDRational(301, 1)), float(reloaded.tag_v2[282]))