[3.9] bpo-44558: Match countOf is/== treatment to c (GH-27007). (GH-27055)

corona10 · web-flow · commit 9761abf30617 · 2021-07-07T23:55:22.000+09:00
diff --git a/Lib/operator.py b/Lib/operator.py
@@ -155,10 +155,10 @@ def contains(a, b):
     return b in a
 
 def countOf(a, b):
-    "Return the number of times b occurs in a."
+    "Return the number of items in a which are, or which equal, b."
     count = 0
     for i in a:
-        if i == b:
+        if i is b or i == b:
             count += 1
     return count
 
diff --git a/Lib/test/test_operator.py b/Lib/test/test_operator.py
@@ -149,6 +149,11 @@ def test_countOf(self):
         self.assertRaises(ZeroDivisionError, operator.countOf, BadIterable(), 1)
         self.assertEqual(operator.countOf([1, 2, 1, 3, 1, 4], 3), 1)
         self.assertEqual(operator.countOf([1, 2, 1, 3, 1, 4], 5), 0)
+        # is but not ==
+        nan = float("nan")
+        self.assertEqual(operator.countOf([nan, nan, 21], nan), 2)
+        # == but not is
+        self.assertEqual(operator.countOf([{}, 1, {}, 2], {}), 2)
 
     def test_delitem(self):
         operator = self.module
diff --git a/Misc/NEWS.d/next/Documentation/2021-07-03-18-25-17.bpo-44558.0pTknl.rst b/Misc/NEWS.d/next/Documentation/2021-07-03-18-25-17.bpo-44558.0pTknl.rst
@@ -0,0 +1,2 @@
+Match the docstring and python implementation of :func:`~operator.countOf` to the behavior
+of its c implementation.
diff --git a/Modules/_operator.c b/Modules/_operator.c
@@ -494,12 +494,12 @@ _operator_indexOf_impl(PyObject *module, PyObject *a, PyObject *b)
 /*[clinic input]
 _operator.countOf = _operator.indexOf
 
-Return the number of times b occurs in a.
+Return the number of items in a which are, or which equal, b.
 [clinic start generated code]*/
 
 static Py_ssize_t
 _operator_countOf_impl(PyObject *module, PyObject *a, PyObject *b)
-/*[clinic end generated code: output=9e1623197daf3382 input=0c3a2656add252db]*/
+/*[clinic end generated code: output=9e1623197daf3382 input=93ea57f170f3f0bb]*/
 {
     return PySequence_Count(a, b);
 }
diff --git a/Modules/clinic/_operator.c.h b/Modules/clinic/_operator.c.h

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Match the docstring and python implementation of :func:`~operator.countOf` to the behavior
	`2`	`+of its c implementation.`
Original file line number	Diff line number	Diff line change
`@@ -494,12 +494,12 @@ _operator_indexOf_impl(PyObject module, PyObject a, PyObject *b)`
`494`	`494`	`/*[clinic input]`
`495`	`495`	`_operator.countOf = _operator.indexOf`
`496`	`496`
`497`		`-Return the number of times b occurs in a.`
	`497`	`+Return the number of items in a which are, or which equal, b.`
`498`	`498`	`[clinic start generated code]*/`
`499`	`499`
`500`	`500`	`static Py_ssize_t`
`501`	`501`	`_operator_countOf_impl(PyObject module, PyObject a, PyObject *b)`
`502`		`-/[clinic end generated code: output=9e1623197daf3382 input=0c3a2656add252db]/`
	`502`	`+/[clinic end generated code: output=9e1623197daf3382 input=93ea57f170f3f0bb]/`
`503`	`503`	`{`
`504`	`504`	`return PySequence_Count(a, b);`
`505`	`505`	`}`