bpo-38159: Clarify documentation of PyState_AddModule (GH-16101)
This was never intented to be called manually from PyInit_*.
Also, clarify PyState_RemoveModule return value.
diff --git a/Doc/c-api/module.rst b/Doc/c-api/module.rst
index 46306b3..57902a9 100644
--- a/Doc/c-api/module.rst
+++ b/Doc/c-api/module.rst
@@ -485,10 +485,21 @@
Only effective on modules created using single-phase initialization.
+ Python calls ``PyState_AddModule`` automatically after importing a module,
+ so it is unnecessary (but harmless) to call it from module initialization
+ code. An explicit call is needed only if the module's own init code
+ subsequently calls ``PyState_FindModule``.
+ The function is mainly intended for implementing alternative import
+ mechanisms (either by calling it directly, or by referring to its
+ implementation for details of the required state updates).
+
+ Return 0 on success or -1 on failure.
+
.. versionadded:: 3.3
.. c:function:: int PyState_RemoveModule(PyModuleDef *def)
Removes the module object created from *def* from the interpreter state.
+ Return 0 on success or -1 on failure.
.. versionadded:: 3.3