Issue #22486: Added the math.gcd() function. The fractions.gcd() function now is

deprecated.  Based on patch by Mark Dickinson.

1 files changed, 51 insertions, 0 deletions

diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 023dea9..fcd78d5 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -175,6 +175,14 @@ def parse_testfile(fname):
                    flags
                   )
 
+# Class providing an __index__ method.
+class MyIndexable(object):
+    def __init__(self, value):
+        self.value = value
+
+    def __index__(self):
+        return self.value
+
 class MathTests(unittest.TestCase):
 
     def ftest(self, name, value, expected):
@@ -595,6 +603,49 @@ class MathTests(unittest.TestCase):
             s = msum(vals)
             self.assertEqual(msum(vals), math.fsum(vals))
 
+    def testGcd(self):
+        gcd = math.gcd
+        self.assertEqual(gcd(0, 0), 0)
+        self.assertEqual(gcd(1, 0), 1)
+        self.assertEqual(gcd(-1, 0), 1)
+        self.assertEqual(gcd(0, 1), 1)
+        self.assertEqual(gcd(0, -1), 1)
+        self.assertEqual(gcd(7, 1), 1)
+        self.assertEqual(gcd(7, -1), 1)
+        self.assertEqual(gcd(-23, 15), 1)
+        self.assertEqual(gcd(120, 84), 12)
+        self.assertEqual(gcd(84, -120), 12)
+        self.assertEqual(gcd(1216342683557601535506311712,
+                             436522681849110124616458784), 32)
+        c = 652560
+        x = 434610456570399902378880679233098819019853229470286994367836600566
+        y = 1064502245825115327754847244914921553977
+        a = x * c
+        b = y * c
+        self.assertEqual(gcd(a, b), c)
+        self.assertEqual(gcd(b, a), c)
+        self.assertEqual(gcd(-a, b), c)
+        self.assertEqual(gcd(b, -a), c)
+        self.assertEqual(gcd(a, -b), c)
+        self.assertEqual(gcd(-b, a), c)
+        self.assertEqual(gcd(-a, -b), c)
+        self.assertEqual(gcd(-b, -a), c)
+        c = 576559230871654959816130551884856912003141446781646602790216406874
+        a = x * c
+        b = y * c
+        self.assertEqual(gcd(a, b), c)
+        self.assertEqual(gcd(b, a), c)
+        self.assertEqual(gcd(-a, b), c)
+        self.assertEqual(gcd(b, -a), c)
+        self.assertEqual(gcd(a, -b), c)
+        self.assertEqual(gcd(-b, a), c)
+        self.assertEqual(gcd(-a, -b), c)
+        self.assertEqual(gcd(-b, -a), c)
+
+        self.assertRaises(TypeError, gcd, 120.0, 84)
+        self.assertRaises(TypeError, gcd, 120, 84.0)
+        self.assertEqual(gcd(MyIndexable(120), MyIndexable(84)), 12)
+
     def testHypot(self):
         self.assertRaises(TypeError, math.hypot)
         self.ftest('hypot(0,0)', math.hypot(0,0), 0)