def from_doi(doi_identifier):
    """
    Make an ISBN out of the given DOI.

    .. note::

        Taken from
        https://github.com/xlcnd/isbnlib/issues/30#issuecomment-167444777.


    .. note::

        See https://github.com/xlcnd/isbnlib#note. The returned ISBN may not be
        issued yet (it is a valid one, but not necessary corresponding to a
        valid book).

    :param doi_identifier: A valid canonical DOI.
    :returns: An ISBN string.

    >>> from_doi('10.978.316/1484100')
    '9783161484100'
    """
    return "".join(c for c in doi_identifier[2:] if c in "0123456789xX")