def restructuredtext(value, settings=RESTRUCTUREDTEXT_SETTINGS):
    """
    RestructuredText processing with optionnally custom settings.
    """
    try:
        from docutils.core import publish_parts
    except ImportError:
        warnings.warn("The Python docutils library isn't installed.",
                      RuntimeWarning)
        return value

    parts = publish_parts(source=force_bytes(value),
                          writer_name='html4css1',
                          settings_overrides=settings)
    return force_text(parts['fragment'])
RestructuredText processing with optionnally custom settings.