using python with tar files and compressed files

[John Salerno]

Here's the name of a file I have: wxPython-newdocs-2.6.3.3.tar.bz2

Now, I tried this:

import tarfile
tar = tarfile.open('wxPython-newdocs-2.6.3.3.tar.bz2', 'r:bz2')

but got this:

Traceback (most recent call last):
   File "<pyshell#5>", line 1, in -toplevel-
     tar = tarfile.open('wxPython-newdocs-2.6.3.3.tar.bz2', 'r:bz2')
   File "C:\Python24\lib\tarfile.py", line 901, in open
     return func(name, filemode, fileobj)
   File "C:\Python24\lib\tarfile.py", line 1006, in bz2open
     raise ReadError, "not a bzip2 file"
ReadError: not a bzip2 file

So I'm a little confused. When dealing with a tar.gz or tar.bz2 file, do 
you need to uncompress it first with the proper module (gzip or bz2)? Or 
does tarfile take care of this? If so, why doesn't it recognize the 
above file? Or am I just doing it the wrong way? (I'm following an 
example in the docs)