bpo-37648: Fixed minor inconsistency in some __contains__. (GH-14904)

The collection's item is now always at the left and
the needle is on the right of ==.

4 files changed, 4 insertions, 6 deletions

diff --git a/Objects/abstract.c b/Objects/abstract.c
index db1c3064db..f93d73fa75 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -2016,7 +2016,7 @@ _PySequence_IterSearch(PyObject *seq, PyObject *obj, int operation)
             break;
         }
 
-        cmp = PyObject_RichCompareBool(obj, item, Py_EQ);
+        cmp = PyObject_RichCompareBool(item, obj, Py_EQ);
         Py_DECREF(item);
         if (cmp < 0)
             goto Fail;
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index b6205d93ca..f168ad5d2f 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -4392,7 +4392,7 @@ dictitems_contains(_PyDictViewObject *dv, PyObject *obj)
         return 0;
     }
     Py_INCREF(found);
-    result = PyObject_RichCompareBool(value, found, Py_EQ);
+    result = PyObject_RichCompareBool(found, value, Py_EQ);
     Py_DECREF(found);
     return result;
 }
diff --git a/Objects/listobject.c b/Objects/listobject.c
index d012ab933a..cea9b24a3b 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -449,8 +449,7 @@ list_contains(PyListObject *a, PyObject *el)
     int cmp;
 
     for (i = 0, cmp = 0 ; cmp == 0 && i < Py_SIZE(a); ++i)
-        cmp = PyObject_RichCompareBool(el, PyList_GET_ITEM(a, i),
-                                           Py_EQ);
+        cmp = PyObject_RichCompareBool(PyList_GET_ITEM(a, i), el, Py_EQ);
     return cmp;
 }
 
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index fc2d2742dd..aeaf845d74 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -403,8 +403,7 @@ tuplecontains(PyTupleObject *a, PyObject *el)
     int cmp;
 
     for (i = 0, cmp = 0 ; cmp == 0 && i < Py_SIZE(a); ++i)
-        cmp = PyObject_RichCompareBool(el, PyTuple_GET_ITEM(a, i),
-                                           Py_EQ);
+        cmp = PyObject_RichCompareBool(PyTuple_GET_ITEM(a, i), el, Py_EQ);
     return cmp;
 }