Partial implementation of the interface provided by zipfile.ZipFile using the unzip command

unzipwrapper.py

from subprocess import Popen, PIPE
from tempfile import TemporaryFile
from os import devnull

class ZipFile(object):
    def __init__(self, filename):
        self.filename = filename
        open(filename).close()

    def __enter__(self):
        self.dn = open(devnull)
        return self

    def __exit__(self, type, value, tb):
        self.dn.close()

    def open(self, path):
        tf = TemporaryFile(prefix='unzipwrapper')
        unzip = Popen(['unzip', '-p', self.filename, path], stdout=PIPE, stderr=self.dn)
        stdout, stderr = unzip.communicate()
        tf.write(stdout)
        tf.seek(0)
        return tf