[Web-SIG] API to add a tree viewer / navigator to a web document ?

[denis]

Folks,
  for one of you experts, this must be trivial / must exist already
within some big Python-web package:

say I'm looking at a long web doc.html which has no tree view on the
left,
but I can hack a local tree view file with level, name, href like

+ 1 US href=  ("+" button expands, "-" folds)
  2 Alabama href=
  3 ...
  2 Alaska href=
  ...
+ 1 Canada href=
  ...

Is there a small API that can generate a tree viewer / navigator from
this,
either side by side in the same browser window with the remote web
pages, or in a separate window ?
(The tree view lines can of course be reformatted to xml or whatever
the API wants.)

There are really 2 APIs here:
a) class TreeView
b) display the tree view and the remote web page in split windows.

(Is there a general introduction to Python-webbing
for someone who knows Python but almost no CSS nor web services ?)

Thanks, cheers
  -- denis