Remove trailing whitespace.
diff --git a/Doc/extending/extending.rst b/Doc/extending/extending.rst
index 8c2268e..8e45384 100644
--- a/Doc/extending/extending.rst
+++ b/Doc/extending/extending.rst
@@ -471,7 +471,7 @@
 :cfunc:`PyEval_CallObject`.  This function has two arguments, both pointers to
 arbitrary Python objects: the Python function, and the argument list.  The
 argument list must always be a tuple object, whose length is the number of
-arguments.  To call the Python function with no arguments, pass in NULL, or 
+arguments.  To call the Python function with no arguments, pass in NULL, or
 an empty tuple; to call it with one argument, pass a singleton tuple.
 :cfunc:`Py_BuildValue` returns a tuple when its format string consists of zero
 or more format codes between parentheses.  For example::
@@ -510,7 +510,7 @@
    if (result == NULL)
        return NULL; /* Pass error back */
    ...use result...
-   Py_DECREF(result); 
+   Py_DECREF(result);
 
 Depending on the desired interface to the Python callback function, you may also
 have to provide an argument list to :cfunc:`PyEval_CallObject`.  In some cases
@@ -535,7 +535,7 @@
 the error check!  Also note that strictly speaking this code is not complete:
 :cfunc:`Py_BuildValue` may run out of memory, and this should be checked.
 
-You may also call a function with keyword arguments by using 
+You may also call a function with keyword arguments by using
 :cfunc:`PyEval_CallObjectWithKeywords`.  As in the above example, we use
 :cfunc:`Py_BuildValue` to construct the dictionary. ::
 
@@ -671,7 +671,7 @@
 
    static PyObject *
    keywdarg_parrot(PyObject *self, PyObject *args, PyObject *keywds)
-   {  
+   {
        int voltage;
        char *state = "a stiff";
        char *action = "voom";
@@ -679,11 +679,11 @@
 
        static char *kwlist[] = {"voltage", "state", "action", "type", NULL};
 
-       if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|sss", kwlist, 
+       if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|sss", kwlist,
                                         &voltage, &state, &action, &type))
-           return NULL; 
+           return NULL;
 
-       printf("-- This parrot wouldn't %s if you put %i Volts through it.\n", 
+       printf("-- This parrot wouldn't %s if you put %i Volts through it.\n",
               action, voltage);
        printf("-- Lovely plumage, the %s -- It's %s!\n", type, state);