def is_empty_or_html(line):
    """Return True for HTML line and empty (or whitespace only) line.

    line -- string

    The Rfam adaptor that retrieves records inlcudes two HTML tags in
    the record. These lines need to be ignored in addition to empty lines. 
    """
    if line.startswith('<pre') or line.startswith('</pre'):
        return True
    return (not line) or line.isspace()