bpo-20092. Use __index__ in constructors of int, float and complex. (GH-13108)

1 files changed, 18 insertions, 0 deletions

diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py
index 21c6eaed60..fe1e566562 100644
--- a/Lib/test/test_complex.py
+++ b/Lib/test/test_complex.py
@@ -368,6 +368,24 @@ class ComplexTest(unittest.TestCase):
         self.assertAlmostEqual(complex(real=float2(17.), imag=float2(23.)), 17+23j)
         self.assertRaises(TypeError, complex, float2(None))
 
+        class MyIndex:
+            def __init__(self, value):
+                self.value = value
+            def __index__(self):
+                return self.value
+
+        self.assertAlmostEqual(complex(MyIndex(42)), 42.0+0.0j)
+        self.assertAlmostEqual(complex(123, MyIndex(42)), 123.0+42.0j)
+        self.assertRaises(OverflowError, complex, MyIndex(2**2000))
+        self.assertRaises(OverflowError, complex, 123, MyIndex(2**2000))
+
+        class MyInt:
+            def __int__(self):
+                return 42
+
+        self.assertRaises(TypeError, complex, MyInt())
+        self.assertRaises(TypeError, complex, 123, MyInt())
+
         class complex0(complex):
             """Test usage of __complex__() when inheriting from 'complex'"""
             def __complex__(self):