bpo-36048: Use __index__() instead of __int__() for implicit conversion if available. (GH-11952)

Deprecate using the __int__() method in implicit conversions of Python
numbers to C integers.

5 files changed, 110 insertions, 13 deletions

diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
index 958b336..715f0ea 100644
--- a/Lib/test/datetimetester.py
+++ b/Lib/test/datetimetester.py
@@ -4918,8 +4918,9 @@ class Oddballs(unittest.TestCase):
         for xx in [decimal.Decimal(10),
                    decimal.Decimal('10.9'),
                    Number(10)]:
-            self.assertEqual(datetime(10, 10, 10, 10, 10, 10, 10),
-                             datetime(xx, xx, xx, xx, xx, xx, xx))
+            with self.assertWarns(DeprecationWarning):
+                self.assertEqual(datetime(10, 10, 10, 10, 10, 10, 10),
+                                 datetime(xx, xx, xx, xx, xx, xx, xx))
 
         with self.assertRaisesRegex(TypeError, '^an integer is required '
                                               r'\(got type str\)$'):
@@ -4927,7 +4928,7 @@ class Oddballs(unittest.TestCase):
 
         f10 = Number(10.9)
         with self.assertRaisesRegex(TypeError, '^__int__ returned non-int '
-                                              r'\(type float\)$'):
+                                               r'\(type float\)$'):
             datetime(10, 10, f10)
 
         class Float(float):
diff --git a/Lib/test/test_array.py b/Lib/test/test_array.py
index 7f402f8..2399980 100644
--- a/Lib/test/test_array.py
+++ b/Lib/test/test_array.py
@@ -1242,6 +1242,8 @@ class IntegerNumberTest(NumberTest):
 class Intable:
     def __init__(self, num):
         self._num = num
+    def __index__(self):
+        return self._num
     def __int__(self):
         return self._num
     def __sub__(self, other):
diff --git a/Lib/test/test_getargs2.py b/Lib/test/test_getargs2.py
index d9bcb1d..07e2d15 100644
--- a/Lib/test/test_getargs2.py
+++ b/Lib/test/test_getargs2.py
@@ -53,6 +53,27 @@ LLONG_MAX = 2**63-1
 LLONG_MIN = -2**63
 ULLONG_MAX = 2**64-1
 
+class Index:
+    def __index__(self):
+        return 99
+
+class IndexIntSubclass(int):
+    def __index__(self):
+        return 99
+
+class BadIndex:
+    def __index__(self):
+        return 1.0
+
+class BadIndex2:
+    def __index__(self):
+        return True
+
+class BadIndex3(int):
+    def __index__(self):
+        return True
+
+
 class Int:
     def __int__(self):
         return 99
@@ -134,7 +155,14 @@ class Unsigned_TestCase(unittest.TestCase):
         from _testcapi import getargs_b
         # b returns 'unsigned char', and does range checking (0 ... UCHAR_MAX)
         self.assertRaises(TypeError, getargs_b, 3.14)
-        self.assertEqual(99, getargs_b(Int()))
+        self.assertEqual(99, getargs_b(Index()))
+        self.assertEqual(0, getargs_b(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_b, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_b(BadIndex2()))
+        self.assertEqual(0, getargs_b(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_b(Int()))
         self.assertEqual(0, getargs_b(IntSubclass()))
         self.assertRaises(TypeError, getargs_b, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -153,7 +181,14 @@ class Unsigned_TestCase(unittest.TestCase):
         from _testcapi import getargs_B
         # B returns 'unsigned char', no range checking
         self.assertRaises(TypeError, getargs_B, 3.14)
-        self.assertEqual(99, getargs_B(Int()))
+        self.assertEqual(99, getargs_B(Index()))
+        self.assertEqual(0, getargs_B(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_B, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_B(BadIndex2()))
+        self.assertEqual(0, getargs_B(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_B(Int()))
         self.assertEqual(0, getargs_B(IntSubclass()))
         self.assertRaises(TypeError, getargs_B, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -172,7 +207,14 @@ class Unsigned_TestCase(unittest.TestCase):
         from _testcapi import getargs_H
         # H returns 'unsigned short', no range checking
         self.assertRaises(TypeError, getargs_H, 3.14)
-        self.assertEqual(99, getargs_H(Int()))
+        self.assertEqual(99, getargs_H(Index()))
+        self.assertEqual(0, getargs_H(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_H, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_H(BadIndex2()))
+        self.assertEqual(0, getargs_H(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_H(Int()))
         self.assertEqual(0, getargs_H(IntSubclass()))
         self.assertRaises(TypeError, getargs_H, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -192,7 +234,14 @@ class Unsigned_TestCase(unittest.TestCase):
         from _testcapi import getargs_I
         # I returns 'unsigned int', no range checking
         self.assertRaises(TypeError, getargs_I, 3.14)
-        self.assertEqual(99, getargs_I(Int()))
+        self.assertEqual(99, getargs_I(Index()))
+        self.assertEqual(0, getargs_I(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_I, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_I(BadIndex2()))
+        self.assertEqual(0, getargs_I(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_I(Int()))
         self.assertEqual(0, getargs_I(IntSubclass()))
         self.assertRaises(TypeError, getargs_I, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -213,6 +262,11 @@ class Unsigned_TestCase(unittest.TestCase):
         # k returns 'unsigned long', no range checking
         # it does not accept float, or instances with __int__
         self.assertRaises(TypeError, getargs_k, 3.14)
+        self.assertRaises(TypeError, getargs_k, Index())
+        self.assertEqual(0, getargs_k(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_k, BadIndex())
+        self.assertRaises(TypeError, getargs_k, BadIndex2())
+        self.assertEqual(0, getargs_k(BadIndex3()))
         self.assertRaises(TypeError, getargs_k, Int())
         self.assertEqual(0, getargs_k(IntSubclass()))
         self.assertRaises(TypeError, getargs_k, BadInt())
@@ -233,7 +287,14 @@ class Signed_TestCase(unittest.TestCase):
         from _testcapi import getargs_h
         # h returns 'short', and does range checking (SHRT_MIN ... SHRT_MAX)
         self.assertRaises(TypeError, getargs_h, 3.14)
-        self.assertEqual(99, getargs_h(Int()))
+        self.assertEqual(99, getargs_h(Index()))
+        self.assertEqual(0, getargs_h(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_h, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_h(BadIndex2()))
+        self.assertEqual(0, getargs_h(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_h(Int()))
         self.assertEqual(0, getargs_h(IntSubclass()))
         self.assertRaises(TypeError, getargs_h, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -252,7 +313,14 @@ class Signed_TestCase(unittest.TestCase):
         from _testcapi import getargs_i
         # i returns 'int', and does range checking (INT_MIN ... INT_MAX)
         self.assertRaises(TypeError, getargs_i, 3.14)
-        self.assertEqual(99, getargs_i(Int()))
+        self.assertEqual(99, getargs_i(Index()))
+        self.assertEqual(0, getargs_i(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_i, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_i(BadIndex2()))
+        self.assertEqual(0, getargs_i(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_i(Int()))
         self.assertEqual(0, getargs_i(IntSubclass()))
         self.assertRaises(TypeError, getargs_i, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -271,7 +339,14 @@ class Signed_TestCase(unittest.TestCase):
         from _testcapi import getargs_l
         # l returns 'long', and does range checking (LONG_MIN ... LONG_MAX)
         self.assertRaises(TypeError, getargs_l, 3.14)
-        self.assertEqual(99, getargs_l(Int()))
+        self.assertEqual(99, getargs_l(Index()))
+        self.assertEqual(0, getargs_l(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_l, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_l(BadIndex2()))
+        self.assertEqual(0, getargs_l(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_l(Int()))
         self.assertEqual(0, getargs_l(IntSubclass()))
         self.assertRaises(TypeError, getargs_l, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -291,6 +366,12 @@ class Signed_TestCase(unittest.TestCase):
         # n returns 'Py_ssize_t', and does range checking
         # (PY_SSIZE_T_MIN ... PY_SSIZE_T_MAX)
         self.assertRaises(TypeError, getargs_n, 3.14)
+        self.assertEqual(99, getargs_n(Index()))
+        self.assertEqual(0, getargs_n(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_n, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_n(BadIndex2()))
+        self.assertEqual(0, getargs_n(BadIndex3()))
         self.assertRaises(TypeError, getargs_n, Int())
         self.assertEqual(0, getargs_n(IntSubclass()))
         self.assertRaises(TypeError, getargs_n, BadInt())
@@ -313,7 +394,14 @@ class LongLong_TestCase(unittest.TestCase):
         # ... LLONG_MAX)
         self.assertRaises(TypeError, getargs_L, 3.14)
         self.assertRaises(TypeError, getargs_L, "Hello")
-        self.assertEqual(99, getargs_L(Int()))
+        self.assertEqual(99, getargs_L(Index()))
+        self.assertEqual(0, getargs_L(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_L, BadIndex())
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(1, getargs_L(BadIndex2()))
+        self.assertEqual(0, getargs_L(BadIndex3()))
+        with self.assertWarns(DeprecationWarning):
+            self.assertEqual(99, getargs_L(Int()))
         self.assertEqual(0, getargs_L(IntSubclass()))
         self.assertRaises(TypeError, getargs_L, BadInt())
         with self.assertWarns(DeprecationWarning):
@@ -332,6 +420,11 @@ class LongLong_TestCase(unittest.TestCase):
         from _testcapi import getargs_K
         # K return 'unsigned long long', no range checking
         self.assertRaises(TypeError, getargs_K, 3.14)
+        self.assertRaises(TypeError, getargs_K, Index())
+        self.assertEqual(0, getargs_K(IndexIntSubclass()))
+        self.assertRaises(TypeError, getargs_K, BadIndex())
+        self.assertRaises(TypeError, getargs_K, BadIndex2())
+        self.assertEqual(0, getargs_K(BadIndex3()))
         self.assertRaises(TypeError, getargs_K, Int())
         self.assertEqual(0, getargs_K(IntSubclass()))
         self.assertRaises(TypeError, getargs_K, BadInt())
diff --git a/Lib/test/test_int.py b/Lib/test/test_int.py
index c048b71..307ca36 100644
--- a/Lib/test/test_int.py
+++ b/Lib/test/test_int.py
@@ -385,7 +385,8 @@ class IntTestCases(unittest.TestCase):
                 class TruncReturnsNonInt(base):
                     def __trunc__(self):
                         return Integral()
-                self.assertEqual(int(TruncReturnsNonInt()), 42)
+                with self.assertWarns(DeprecationWarning):
+                    self.assertEqual(int(TruncReturnsNonInt()), 42)
 
                 class NonIntegral(trunc_result_base):
                     def __trunc__(self):
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index bf5d64c..f828b4c 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -914,7 +914,7 @@ LAERTES
 
 
 class CustomInt:
-    def __int__(self):
+    def __index__(self):
         return 100