bpo-38600: Change the mark up of NULL in the C API documentation. (GH-16950)
Replace all *NULL* with ``NULL``.
diff --git a/Doc/c-api/mapping.rst b/Doc/c-api/mapping.rst
index 4244b47..4015f43 100644
--- a/Doc/c-api/mapping.rst
+++ b/Doc/c-api/mapping.rst
@@ -29,7 +29,7 @@
.. c:function:: PyObject* PyMapping_GetItemString(PyObject *o, const char *key)
- Return element of *o* corresponding to the string *key* or *NULL* on failure.
+ Return element of *o* corresponding to the string *key* or ``NULL`` on failure.
This is the equivalent of the Python expression ``o[key]``.
See also :c:func:`PyObject_GetItem`.
@@ -79,7 +79,7 @@
.. c:function:: PyObject* PyMapping_Keys(PyObject *o)
On success, return a list of the keys in object *o*. On failure, return
- *NULL*.
+ ``NULL``.
.. versionchanged:: 3.7
Previously, the function returned a list or a tuple.
@@ -88,7 +88,7 @@
.. c:function:: PyObject* PyMapping_Values(PyObject *o)
On success, return a list of the values in object *o*. On failure, return
- *NULL*.
+ ``NULL``.
.. versionchanged:: 3.7
Previously, the function returned a list or a tuple.
@@ -97,7 +97,7 @@
.. c:function:: PyObject* PyMapping_Items(PyObject *o)
On success, return a list of the items in object *o*, where each item is a
- tuple containing a key-value pair. On failure, return *NULL*.
+ tuple containing a key-value pair. On failure, return ``NULL``.
.. versionchanged:: 3.7
Previously, the function returned a list or a tuple.