def _unescape_separator(option, opt_str, value, parser):
    "\n    Unescape special symbols (like newline)\n\n    When --rs '\n' passed to ydbf.dump, OptionParser saves it as\n    '\\n', i.e. escapes it. We want to unescape special symbols\n    like '\n', '\r', '\t' both in record and field separators\n    "
    if value is not None:
        replacements = ('\\n', '\n'), ('\\r', '\r'), ('\\t', '\t')
        for what, replace_by in replacements:
            value = value.replace(what, replace_by)
    setattr(parser.values, option.dest, value)
