a document I would like to see...

[Skip Montanaro]

    Mark> A text file containing one-line summaries of everything in the
    Mark> standard library, including module name.

    Mark> Then I could do things like this:

    Mark> grep dircmp                  # what module is dircmp in?
    Mark> grep sort                    # what are my options for sorting?
    Mark> grep print | grep -v xmllib  # what can print, ignoring xmllib?

    Mark> Any such thing exist?

What do you have in mind format-wise?  Note that most modules and packages
are sufficiently complex that trying to jam the entire api into a one-line
summary is going to provide fairly meaningless output.  Bop on over to your
local HTML lib docs and try

    egrep -l dircmp *.html

On a 2.2.3 system I see

    contents.html
    dircmp-objects.html
    genindex.html
    index.html
    lib.html
    module-filecmp.html
    module-popen2.html
    obsolete-modules.html

Restricting to *module*.html helps.  "sort" is even worse:

    % egrep -l sort *module*.html
    module-bisect.html
    module-difflib.html
    module-email.Message.html
    module-formatter.html
    module-gdbm.html
    module-locale.html
    module-profile.html
    module-smtplib.html
    module-Tix.html
    module-xml.dom.html
    module-xmllib.html

I realize that's not quite what you were asking.  If you could provide a
more detailed example perhaps someone can make some more on-target
suggestions.

Skip