Minor nit that fixes a bunch of indexing: the way the classdesc

environment saves the name of the last class described, method and
member descriptions were not picking it up correctly.  Thus, many
index entries were described as "( method)" instead of "(FooClass
method)".  Multiple entries were collapsed in the index when
methods/members from multiple classes share the same name.

Doc/texinputs/python.sty

@@ -502,7 +502,8 @@
 % classes ----------------------------------------------------------------
 % \begin{classdesc}{name}{constructor args}
 \newenvironment{classdesc}[2]{
-  \renewcommand{\py@thisclass}{#1}
+  % Using \renewcommand doesn't work for this, for unknown reasons:
+  \global\def\py@thisclass{#1}
   \begin{fulllineitems}
     \item[\code{\bfcode{#1}(\py@varvars{#2})}%
       \withsubitem{(class in \py@thismodule)}{\ttindex{#1}}]