Move the change to ending the abstract from python.sty to manual.cls; it
is not appropriate for the howto document class.
diff --git a/Doc/texinputs/manual.cls b/Doc/texinputs/manual.cls
index 51d7baf..2e7f40e 100644
--- a/Doc/texinputs/manual.cls
+++ b/Doc/texinputs/manual.cls
@@ -75,6 +75,20 @@
 }
 
 
+% Catch the end of the {abstract} environment, but here make sure the
+% abstract is followed by a blank page if the 'openright' option is used.
+%
+\let\OldEndAbstract=\endabstract
+\renewcommand{\endabstract}{
+  \if@openright
+    \ifodd\value{page}
+      \typeout{Adding blank page after the abstract.}
+      \vfil\pagebreak
+    \fi
+  \fi
+  \OldEndAbstract
+}
+
 % This wraps the \tableofcontents macro with all the magic to get the
 % spacing right and have the right number of pages if the 'openright'
 % option has been used.  This eliminates a fair amount of crud in the