Can't figure out how to handle .gz files with no content list (initrd.gz example)

test code:

    FILE="/Users/magregor/src/imgunbundle/test/test_data/isolinux/initrd.gz"
    import sys, os
    import pprint
    import libarchive.public as la
    with open(FILE, 'rb') as fh:
        with la.file_reader(fh.name) as lafh:
            count = 0
            for count,entry in enumerate(lafh):
                print str(entry)
                #print entry.filetype
                pprint.pprint(dir(entry.filetype))
            if not count:
                outfile = os.path.splitext(os.path.basename(FILE))[0]
                for entry in la.file_pour(FILE):
                    print(entry)
                print(outfile)
                raise Exception('No count')

result:

    Traceback (most recent call last):
      File "/Users/magregor/tmp/test_lafh.py", line 18, in <module>
        raise Exception('No count')
    Exception: No count

dsoprea / PyEasyArchive

Can't figure out how to handle .gz files with no content list (initrd.gz example) #19