def _mpfr_get_str2(base, ndigits, op, rounding_mode):
    """
    Variant of mpfr_get_str, for internal use:  simply splits off the '-'
    sign from the digit string, and returns a triple

        (sign, digits, exp)

    Also converts the byte-string produced by mpfr_get_str to Unicode.

    """
    digits, exp = mpfr.mpfr_get_str(base, ndigits, op, rounding_mode)
    negative = digits.startswith('-')
    if negative:
        digits = digits[1:]
    return negative, digits, exp