Issue #8294: Allow float and Decimal arguments in Fraction constructor.

1 files changed, 26 insertions, 1 deletions

diff --git a/Lib/test/test_fractions.py b/Lib/test/test_fractions.py
index a24fcd3c3a..7f0c428f6b 100644
--- a/Lib/test/test_fractions.py
+++ b/Lib/test/test_fractions.py
@@ -12,6 +12,11 @@ from cPickle import dumps, loads
 F = fractions.Fraction
 gcd = fractions.gcd
 
+# decorator for skipping tests on non-IEEE 754 platforms
+requires_IEEE_754 = unittest.skipUnless(
+    float.__getformat__("double").startswith("IEEE"),
+    "test requires IEEE 754 doubles")
+
 class DummyFloat(object):
     """Dummy float class for testing comparisons with Fractions"""
 
@@ -137,13 +142,33 @@ class FractionTest(unittest.TestCase):
 
         self.assertRaisesMessage(ZeroDivisionError, "Fraction(12, 0)",
                                  F, 12, 0)
-        self.assertRaises(TypeError, F, 1.5)
         self.assertRaises(TypeError, F, 1.5 + 3j)
 
         self.assertRaises(TypeError, F, "3/2", 3)
         self.assertRaises(TypeError, F, 3, 0j)
         self.assertRaises(TypeError, F, 3, 1j)
 
+    @requires_IEEE_754
+    def testInitFromFloat(self):
+        self.assertEquals((5, 2), _components(F(2.5)))
+        self.assertEquals((0, 1), _components(F(-0.0)))
+        self.assertEquals((3602879701896397, 36028797018963968),
+                          _components(F(0.1)))
+        self.assertRaises(TypeError, F, float('nan'))
+        self.assertRaises(TypeError, F, float('inf'))
+        self.assertRaises(TypeError, F, float('-inf'))
+
+    def testInitFromDecimal(self):
+        self.assertEquals((11, 10),
+                          _components(F(Decimal('1.1'))))
+        self.assertEquals((7, 200),
+                          _components(F(Decimal('3.5e-2'))))
+        self.assertEquals((0, 1),
+                          _components(F(Decimal('.000e20'))))
+        self.assertRaises(TypeError, F, Decimal('nan'))
+        self.assertRaises(TypeError, F, Decimal('snan'))
+        self.assertRaises(TypeError, F, Decimal('inf'))
+        self.assertRaises(TypeError, F, Decimal('-inf'))
 
     def testFromString(self):
         self.assertEquals((5, 1), _components(F("5")))