Sample usage:: >>> base20 = BaseConverter('0123456789abcdefghij') >>> base20.encode(1234) '31e' >>> base20.decode('31e') 1234 >>> base20.encode(-1234) '-31e' >>> base20.decode('-31e') -1234 >>> base11 = BaseConverter('0123456789-', sign='$') >>> base11.encode('$1234') '$-22' >>> base11.decode('$-22') '$1234'source link