Read tar.gz files without extracting

I had a need to look for certain commands in a list of Oracle audit logs what had been tarred and zipped (*.tar.gz format). I created a list with an ls command:

ls *.gz > dean.txt

I then used the below python code to read through the zipped tar balls looking for certain strings:

#!/usr/bin/python
import tarfile,os
import sys
 
list_of_tar = open('dean.txt', 'r')
for tar_name in list_of_tar:
    tar_name = tar_name.rstrip()
    print tar_name
    tar = tarfile.open(tar_name,'r:gz')
    for member in tar.getnames():
        file_name=tar.extractfile(member)
        for line in file_name:
            line = line.lower()
            if 'alter ' in line:
                if ' system ' in line:
                    if 'kill' in line:
                        print tar_name, member , line
tar.close()

This was a quick and dirty python to fulfill an immediate need. With more time the search condition could be improved.