Expand one level of symbolic link in sys.argv[0] before inserting its dirname in sys.path. This means that you can create a symbolic link foo in /usr/local/bin pointing to /usr/yourname/src/foo/foo.py, and then invoking foo will insert /usr/yourname/src/foo in sys.path, not /usr/local/bin. This makes it easier to have multifile programs (before, the program would have to do an os.readlink(sys.argv[0]) itself and insert the resulting directory in sys.path -- Grail does this). Note that the expansion is only used for sys.path; sys.argv[0] is still the original, unadorned filename (/usr/local/bin/foo in the example).