First Python Program - Multiple Errors
<p>I am trying to write a python program that will eventually take a command line argument of a file, determine if its a tar or zip etc file and then exctract it accordingly.  I am just trying to get the tar part working now and I am getting multiple errors.  The file I am checking for resides in my ~/ directory.  Any ideas would be great.</p>

<pre><code>#!/usr/bin/python

import tarfile
import os

def open_tar(file):
    if tarfile.is_tarfile(file):
        try:
            tar = tarfile.open("file")
            tar.extractall()
            tar.close()
        except ReadError:
            print "File is somehow invalid or can not be handled by tarfile"
        except CompressionError:
            print "Compression method is not supported or data cannot be decoded"
        except StreamError:
            print "Is raised for the limitations that are typical for stream-like TarFile objects."
        except ExtractError:
            print "Is raised for non-fatal errors when using TarFile.extract(), but only if TarFile.errorlevel== 2."

if __name__ == '__main__':
    file = "xampp-linux-1.7.3a.tar.gz"
    print os.getcwd()
    print file
    open_tar(file)
</code></pre>

<p>Here are the errors.  IF I comment out the Read Error, I just get teh same error on the next exception as well.</p>

<pre><code>tux@crosnet:~$ python openall.py
/home/tux
xampp-linux-1.7.3a.tar.gz
Traceback (most recent call last):
  File "openall.py", line 25, in &lt;module&gt;
    open_tar(file)
  File "openall.py", line 12, in open_tar
    except ReadError:
NameError: global name 'ReadError' is not defined
tux@crosnet:~$ 
</code></pre>
