如何正确解码十进制字符串中的转义序列

def decode_decimal_string(decimal_string):
    result = ""
    i = 0

    while i < len(decimal_string):
        if decimal_string[i] == "\\":
            if i+1 < len(decimal_string) and decimal_string[i+1].isdigit():
                decimal = ""
                j = i + 1
                while j < len(decimal_string) and decimal_string[j].isdigit():
                    decimal += decimal_string[j]
                    j += 1

                if decimal:
                    ascii_char = chr(int(decimal))
                    result += ascii_char
                    i = j - 1
                else:
                    result += decimal_string[i]
            else:
                result += decimal_string[i]
        else:
            result += decimal_string[i]

        i += 1

    return result