\citetitle:  Format the title, not the optional URL!
diff --git a/Doc/texinputs/python.sty b/Doc/texinputs/python.sty
index 579aade..9d0db97 100644
--- a/Doc/texinputs/python.sty
+++ b/Doc/texinputs/python.sty
@@ -811,7 +811,7 @@
 
 % cited titles:  \citetitle{Title of Work}
 %       online:  \citetitle[url-to-resource]{Title of Work}
-\newcommand{\citetitle}[2][URL]{\emph{#1}}
+\newcommand{\citetitle}[2][URL]{\emph{#2}}
 
 
 % Deprecation stuff.