Issue #9165: Add math.isfinite and cmath.isfinite.

2 files changed, 18 insertions, 0 deletions

diff --git a/Lib/test/test_cmath.py b/Lib/test/test_cmath.py
index e6c80d2..a589f8d 100644
--- a/Lib/test/test_cmath.py
+++ b/Lib/test/test_cmath.py
@@ -442,6 +442,15 @@ class CMathTests(unittest.TestCase):
         self.assertCEqual(rect(1, pi/2), (0, 1.))
         self.assertCEqual(rect(1, -pi/2), (0, -1.))
 
+    def test_isfinite(self):
+        real_vals = [float('-inf'), -2.3, -0.0,
+                     0.0, 2.3, float('inf'), float('nan')]
+        for x in real_vals:
+            for y in real_vals:
+                z = complex(x, y)
+                self.assertEquals(cmath.isfinite(z),
+                                  math.isfinite(x) and math.isfinite(y))
+
     def test_isnan(self):
         self.assertFalse(cmath.isnan(1))
         self.assertFalse(cmath.isnan(1j))
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 12e7f98..90bd363 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -915,6 +915,15 @@ class MathTests(unittest.TestCase):
         self.assertRaises(TypeError, math.trunc, 1, 2)
         self.assertRaises(TypeError, math.trunc, TestNoTrunc())
 
+    def testIsfinite(self):
+        self.assertTrue(math.isfinite(0.0))
+        self.assertTrue(math.isfinite(-0.0))
+        self.assertTrue(math.isfinite(1.0))
+        self.assertTrue(math.isfinite(-1.0))
+        self.assertFalse(math.isfinite(float("nan")))
+        self.assertFalse(math.isfinite(float("inf")))
+        self.assertFalse(math.isfinite(float("-inf")))
+
     def testIsnan(self):
         self.assertTrue(math.isnan(float("nan")))
         self.assertTrue(math.isnan(float("inf")* 0.))