def versionize(app, pagename, templatename, context, doctree):
 if (not (app.config.canonical_root and app.config.versions)):
  return
 context['versions'] = [(vs, _build_url(app.config.canonical_root, vs, pagename)) for vs in app.config.versions.split(',') if (vs != app.config.version)]

def versionize ( app , pagename , templatename , context , doctree ) : if ( not ( app . config . canonical_root and app . config . versions ) ) : return context [ 'versions' ] = [ ( vs , _build_url ( app . config . canonical_root , vs , pagename ) ) for vs in app . config . versions . split ( ',' ) if ( vs != app . config . version ) ]
adds a version switcher below the menu .