index.js

var tar = require('tar'),
sax = require('sax');


process.stdin
.pipe(tar.Parse())
.on("extendedHeader", function (e) {
})
.on("ignoredEntry", function (e) {
})
.on("longLinkpath", function (e) {
})
.on("longPath", function (e) {
})
.on("entry", function (e) {
    // console.error("entry", e.props);
    e.on("data", function (c) {
        // console.log(c):
    });
    e.on("end", function () {
        // console.error("  <<<EOF");
    });
});

index.py

import tarfile, sys

tar = tarfile.open(fileobj=sys.stdin, mode='r|')
for f in tar:
    pass