Added definition for pardir ('..')

Lib/os.py

@@ -2,9 +2,10 @@
 
 # This exports:
 # - all functions from either posix or mac, e.g., os.unlink, os.stat, etc.
-# - os.path is either module path or macpath
+# - os.path is either module posixpath or macpath
 # - os.name is either 'posix' or 'mac'
 # - os.curdir is a string representing the current directory ('.' or ':')
+# - os.pardir is a string representing the parent directory ('..' or '::')
 
 # Programs that import and use 'os' stand a better chance of being
 # portable between different platforms.  Of course, they must then
@@ -12,15 +13,21 @@
 # and opendir), and leave all pathname manipulation to os.path
 # (e.g., split and join).
 
+# XXX This will need to distinguish between real posix and MS-DOS emulation
+
 try:
 	from posix import *
 	name = 'posix'
 	curdir = '.'
-	import path
+	pardir = '..'
+	import posixpath
+	path = posixpath
+	del posixpath
 except ImportError:
 	from mac import *
 	name = 'mac'
 	curdir = ':'
+	pardir = '::'
 	import macpath
 	path = macpath
 	del macpath