__file__ vs __FILE__

[klenwell]

I apologize in advance for coming at this from this angle but...

In PHP you have the __FILE__ constant which gives you the value of the
absolute path of the file you're in (as opposed to the main script
file.)  With the function dirname, this makes it easy to get the
parent dir of a particular file from within that file:

$parent_dir = dirname(__FILE__);

I'm looking for the best way to accomplish this in Python.  This seems
to work:

parent_dir = os.path.normpath(os.path.join(os.path.abspath(__file__),
'..'))

Can anyone confirm the reliability of this method or suggest a better
(one-line) method for accomplishing this?

Thanks,
Tom