SF patch #461781 by Chris Lawrence: os.path.realpath - Resolve symlinks:

Once upon a time, I put together a little function
   that tries to find the canonical filename for a given
   pathname on POSIX. I've finally gotten around to
   turning it into a proper patch with documentation.
   On non-POSIX, I made it an alias for 'abspath', as
   that's the behavior on POSIX when no symlinks are
   encountered in the path.

   Example:
   >>> os.path.realpath('/usr/bin/X11/X')
   '/usr/X11R6/bin/X'

Doc/lib/libposixpath.tex

@@ -137,6 +137,13 @@ case (use \function{normcase()} for that).  On Windows, it converts
 forward slashes to backward slashes.
 \end{funcdesc}
 
+\begin{funcdesc}{realpath}{path}
+Return the canonical path of the specified filename, eliminating any
+symbolic links encountered in the path.
+Availability:  \UNIX{}.
+\versionadded{2.2}
+\end{funcdesc}
+
 \begin{funcdesc}{samefile}{path1, path2}
 Return true if both pathname arguments refer to the same file or
 directory (as indicated by device number and i-node number).