os.path: Remove external / ffi dependencies in os.path.

This work was funded by Planet Innovation.

Signed-off-by: Andrew Leech <andrew.leech@planetinnovation.com.au>

python-stdlib/os-path/manifest.py

@@ -1,4 +1,4 @@
-metadata(version="0.1.3")
+metadata(version="0.1.4")
 
 # Originally written by Paul Sokolovsky.
 

python-stdlib/os-path/os/path.py

@@ -47,7 +47,11 @@ def basename(path):
 
 
 def exists(path):
-    return os.access(path, os.F_OK)
+    try:
+        os.stat(path)
+        return True
+    except OSError:
+        return False
 
 
 # TODO
@@ -55,11 +59,9 @@ lexists = exists
 
 
 def isdir(path):
-    import stat
-
     try:
         mode = os.stat(path)[0]
-        return stat.S_ISDIR(mode)
+        return mode & 0o040000
     except OSError:
         return False