Return 1 if exists, 0 if created

Doc/c-api/import.rst

@@ -104,10 +104,10 @@ Importing Modules
 
    - If the module name is already present in :data:`sys.modules`,
      set *\*module* to a :term:`strong reference` to the existing module, and
-     return 0.
+     return 1.
    - If the module does not exist in :data:`sys.modules`, create a new empty
      module, store it in :data:`sys.modules`, set *\*module* to a :term:`strong
-     reference` to the module, and return 1.
+     reference` to the module, and return 0.
    - On error, raise an exception, set *\*module* to NULL, and return -1.
 
    The *name* argument may be of the form ``package.module``. Package

Lib/test/test_import/__init__.py

@@ -2678,7 +2678,7 @@ def test_pyimport_addmodule(self):
             __name__,  # package.module
         ):
             self.assertIn(name, sys.modules)
-            _testcapi.check_pyimport_addmodule(name, False)
+            _testcapi.check_pyimport_addmodule(name, True)
 
     def test_pyimport_addmodule_create(self):
         # gh-105922: Test PyImport_ImportOrAddModule(): create a new module.
@@ -2687,7 +2687,7 @@ def test_pyimport_addmodule_create(self):
         self.assertNotIn(name, sys.modules)
         self.addCleanup(unload, name)
 
-        mod = _testcapi.check_pyimport_addmodule(name, True)
+        mod = _testcapi.check_pyimport_addmodule(name, False)
         self.assertIs(mod, sys.modules[name])
 
 

Modules/_testcapimodule.c

@@ -3036,8 +3036,8 @@ static PyObject *
 check_pyimport_addmodule(PyObject *self, PyObject *args)
 {
     const char *name;
-    int is_new;
-    if (!PyArg_ParseTuple(args, "si", &name, &is_new)) {
+    int expected;
+    if (!PyArg_ParseTuple(args, "si", &name, &expected)) {
         return NULL;
     }
 
@@ -3047,7 +3047,7 @@ check_pyimport_addmodule(PyObject *self, PyObject *args)
     if (res < 0) {
         return NULL;
     }
-    assert(res == is_new);
+    assert(res == expected);
     assert(PyModule_Check(module));
     // module is a strong reference
 

Python/import.c

@@ -290,7 +290,7 @@ PyImport_GetModule(PyObject *name)
    First check the modules dictionary if there's one there,
    if not, create a new one and insert it in the modules dictionary. */
 static PyObject *
-import_import_or_add_module(PyThreadState *tstate, PyObject *name, int *is_new)
+import_import_or_add_module(PyThreadState *tstate, PyObject *name, int *exists)
 {
     PyObject *modules = MODULES(tstate->interp);
     if (modules == NULL) {
@@ -304,8 +304,8 @@ import_import_or_add_module(PyThreadState *tstate, PyObject *name, int *is_new)
         return NULL;
     }
     if (m != NULL && PyModule_Check(m)) {
-        if (is_new) {
-            *is_new = 0;
+        if (exists) {
+            *exists = 1;
         }
         return m;
     }
@@ -320,8 +320,8 @@ import_import_or_add_module(PyThreadState *tstate, PyObject *name, int *is_new)
         return NULL;
     }
 
-    if (is_new) {
-        *is_new = 1;
+    if (exists) {
+        *exists = 0;
     }
     return m;
 }
@@ -343,16 +343,16 @@ PyImport_ImportOrAddModule(const char *name, PyObject **pmodule)
         return -1;
     }
     PyThreadState *tstate = _PyThreadState_GET();
-    int is_new;
-    PyObject *module = import_import_or_add_module(tstate, name_obj, &is_new);
+    int exists;
+    PyObject *module = import_import_or_add_module(tstate, name_obj, &exists);
     Py_DECREF(name_obj);
 
     *pmodule = module;
     if (module == NULL) {
         assert(PyErr_Occurred());
         return -1;
     }
-    return is_new;
+    return exists;
 }