Verify the integrity of the tar file with tarfile module?

[rudson alves]

Hello,

I took a Slackware package file .tar (uncompressed) and edited with random characters to generate any error in its structure, as shown in the test bash below:
  
$ tar -tf zoo.tar
./
install/
install/slack-desc
tar: Pulando para o próximo cabeçalho
tar: Exiting with failure status due to previous errors
$ echo $?
2 

How can I verify the integrity of the tar file with tarfile module without having to expand it?

To be more precise, even expanding this file it not generated any error message.