Yields 3-tuples of (name, modified, bytes).

def extract_zip(fileobj):
    """Yields 3-tuples of (name, modified, bytes)."""
    archive = zipfile.ZipFile(fileobj, mode='r')
    filenames = archive.namelist()

    for src_name, dst_name in filter_tzfiles(filenames):
        modified = archive.getinfo(src_name).date_time
        bytes = archive.read(src_name)

        yield dst_name, modified, bytes