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'
diff --git a/Lib/plat-riscos/riscospath.py b/Lib/plat-riscos/riscospath.py
index 32f39ba..8eda834 100644
--- a/Lib/plat-riscos/riscospath.py
+++ b/Lib/plat-riscos/riscospath.py
@@ -315,6 +315,10 @@
     return normpath(join(os.getcwd(), p))
 
 
+# realpath is a no-op on systems without islink support
+realpath = abspath
+
+
 # Normalize a path. Only special path element under RISC OS is "^" for "..".
 
 def normpath(p):