BUG: core: allow scalar type richcompare to call ndarray-subclass methods

pv · pv · commit da40eba435d2 · 2014-05-14T21:37:16.000+03:00
This makes the scalar richcmp behave exactly as
"array(self) &lt;op&gt; other". The difference comes in when "other" is an ndarray
subclass, in which case this change allows the subclass to override the
comparison operations via usual Python binop dispatch rules.
diff --git a/numpy/core/src/multiarray/scalartypes.c.src b/numpy/core/src/multiarray/scalartypes.c.src
@@ -1082,7 +1082,11 @@ gentype_richcompare(PyObject *self, PyObject *other, int cmp_op)
     if (arr == NULL) {
         return NULL;
     }
-    ret = Py_TYPE(arr)->tp_richcompare(arr, other, cmp_op);
+    /*
+     * Call via PyObject_RichCompare to ensure that other.__eq__
+     * has a chance to run when necessary
+     */
+    ret = PyObject_RichCompare(arr, other, cmp_op);
     Py_DECREF(arr);
     return ret;
 }
diff --git a/numpy/core/tests/test_regression.py b/numpy/core/tests/test_regression.py
@@ -1993,6 +1993,16 @@ def __array__(self,*args,**kwargs):
         assert_(not op.eq(lhs, rhs))
         assert_(op.ne(lhs, rhs))
 
+    def test_richcompare_scalar_and_subclass(self):
+        # gh-4709
+        class Foo(np.ndarray):
+            def __eq__(self, other):
+                return "OK"
+        x = np.array([1,2,3]).view(Foo)
+        assert_equal(10 == x, "OK")
+        assert_equal(np.int32(10) == x, "OK")
+        assert_equal(np.array([10]) == x, "OK")
+
 
 if __name__ == "__main__":
     run_module_suite()

Original file line number	Diff line number	Diff line change
`@@ -1082,7 +1082,11 @@ gentype_richcompare(PyObject self, PyObject other, int cmp_op)`
`1082`	`1082`	`if (arr == NULL) {`
`1083`	`1083`	`return NULL;`
`1084`	`1084`	`}`
`1085`		`- ret = Py_TYPE(arr)->tp_richcompare(arr, other, cmp_op);`
	`1085`	`+ /*`
	`1086`	`+ * Call via PyObject_RichCompare to ensure that other.__eq__`
	`1087`	`+ * has a chance to run when necessary`
	`1088`	`+ */`
	`1089`	`+ ret = PyObject_RichCompare(arr, other, cmp_op);`
`1086`	`1090`	`Py_DECREF(arr);`
`1087`	`1091`	`return ret;`
`1088`	`1092`	`}`