# find the best comment line and un-comment or add after

            def add_after_comment(m):

                """process a section comment line and add new value"""

                line = m.group(0)

                key, line_value = m.groups()

                if key not in section_settings:

                    return line

                if line_value != add_after_key_value.get(key):

                    return line

                new_value = section_settings[key]

                if new_value == line_value:

                    line = line.lstrip('#')

                else:

                    line += '\n%s = %s' % (key, new_value)

                section_settings.pop(key)

                return line

            lines = re.sub(r'^#([^#\n\s]*)[ \t]*=[ \t]*(.*)$', add_after_comment, lines, flags=re.MULTILINE)

            # 3rd pass:

            # settings that haven't been consumed yet at is appended to section

            if section_settings:

                lines += '\n' + ''.join('%s = %s\n' % (key, value) for key, value in sorted(section_settings.items()))

    # process sections until comments before next section or end

    ini_lines = re.sub(r'''^

        (\[.*\])\n

        # after the section name, a number of chunks with:

        (

            (?:

                # a number of comments or empty lines

                (?:[#].*\n|\n)*

                # one or more non-empty non-comments non-section-start lines

                (?:[^\n#[].*\n)+

                # a number of comments - not empty lines

                (?:[#].*\n)*

            )*

        )

        ''',

        process_section, ini_lines, flags=re.MULTILINE | re.VERBOSE) \

        + \

        ''.join(

            '\n' + sectionname + '\n' + ''.join('%s = %s\n' % (key, value) for key, value in sorted(section_settings.items()))

            for sectionname, section_settings in sorted(settings.items())

            if section_settings)

    return ini_lines