Issue #26282: PyArg_ParseTupleAndKeywords() and Argument Clinic now support

positional-only and keyword parameters in the same function.

Doc/c-api/arg.rst

@@ -406,8 +406,15 @@ API Functions
 .. c:function:: int PyArg_ParseTupleAndKeywords(PyObject *args, PyObject *kw, const char *format, char *keywords[], ...)
 
    Parse the parameters of a function that takes both positional and keyword
-   parameters into local variables.  Returns true on success; on failure, it
-   returns false and raises the appropriate exception.
+   parameters into local variables.  The *keywords* argument is a
+   *NULL*-terminated array of keyword parameter names.  Empty names denote
+   :ref:`positional-only parameters <positional-only_parameter>`.
+   Returns true on success; on failure, it returns false and raises the
+   appropriate exception.
+
+   .. versionchanged:: 3.6
+      Added support for :ref:`positional-only parameters
+      <positional-only_parameter>`.
 
 
 .. c:function:: int PyArg_VaParseTupleAndKeywords(PyObject *args, PyObject *kw, const char *format, char *keywords[], va_list vargs)

Doc/glossary.rst

@@ -718,6 +718,8 @@ Glossary
 
            def func(foo, bar=None): ...
 
+      .. _positional-only_parameter:
+
       * :dfn:`positional-only`: specifies an argument that can be supplied only
         by position.  Python has no syntax for defining positional-only
         parameters.  However, some built-in functions have positional-only

Doc/whatsnew/3.6.rst

@@ -503,6 +503,11 @@ Build and C API Changes
 * New :c:func:`Py_FinalizeEx` API which indicates if flushing buffered data
   failed (:issue:`5319`).
 
+* :c:func:`PyArg_ParseTupleAndKeywords` now supports :ref:`positional-only
+  parameters <positional-only_parameter>`.  Positional-only parameters are
+  defined by empty names.
+  (Contributed by Serhit Storchaka in :issue:`26282`).
+
 
 Deprecated
 ==========