An archive class, allowing easy access to files in a TAR

archive.py

class Archive(object):
    """Easy interface to `tarfile`.
 
    We use buffered `tar` files to communicate with Docker
    containers. This class provides an easy way to create
    `tar` buffers on the fly, or read from them.
 
    Methods in this class can be chained JS style."""
    def __init__(self, mode, data=None):
        self.file = io.BytesIO(data)
        self.tar = tarfile.open(mode=mode, fileobj=self.file)
 
    def add_text_file(self, filename: str, text: str, encoding='utf-8'):
        """Add the contents of `text` to a new entry in the `tar`
        file.
 
        :return:
            self
        """
        b = text.encode(encoding)
        f = io.BytesIO(b)
        info = tarfile.TarInfo(filename)
        info.size = len(b)
        info.type = tarfile.REGTYPE
 
        self.tar.addfile(info, fileobj=f)
        return self
 
    def get_text_file(self, filename: str, encoding='utf-8') -> str:
        """Read the contents of a file in the archive.
 
        :return:
            contents of file in string.
        """
        return self.tar.extractfile(filename).read().decode(encoding)
 
    def close(self):
        self.tar.close()
        return self
 
    @property
    def buffer(self):
        return self.file.getvalue()