bpo-42528: Improve the docs of most Py*_Check{,Exact} API calls (GH-23602)
I think that none of these API calls can fail, but only few of them are
documented as such. Add the sentence "This function always succeeds" (which is
the same already used e.g. by PyNumber_Check) to all of them.diff --git a/Doc/c-api/cell.rst b/Doc/c-api/cell.rst
index 8408f7e..ac4ef5a 100644
--- a/Doc/c-api/cell.rst
+++ b/Doc/c-api/cell.rst
@@ -27,7 +27,8 @@
.. c:function:: int PyCell_Check(ob)
- Return true if *ob* is a cell object; *ob* must not be ``NULL``.
+ Return true if *ob* is a cell object; *ob* must not be ``NULL``. This
+ function always succeeds.
.. c:function:: PyObject* PyCell_New(PyObject *ob)