> I am getting this error. I assume you mean the email subject. It doesn't work in 3.8 either:
>>> import decimal >>> d = decimal.Decimal(3.5) >>> d Decimal('3.5') >>> import marshal >>> marshal.dumps(d) Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: unmarshallable object but that's not surprising to me. The marshal module is more-or-less meant to serialize Python byte code. Pickle is more generally used for object serialization. Why not use it? >>> import pickle, decimal >>> d = decimal.Decimal(3.5) >>> pickle.dumps(d) b'\x80\x04\x95!\x00\x00\x00\x00\x00\x00\x00\x8c\x07decimal\x94\x8c\x07Decimal\x94\x93\x94\x8c\x033.5\x94\x85\x94R\x94.' That's meant more for serialization of data objects. Skip -- https://mail.python.org/mailman/listinfo/python-list