PyMoney

I think the current design (pre-pep version 1.9) puts too much into an individual unit of money.

An instance of Money should probably have only an amount and a currency (and possibly a timestamp). These should be (immutable) values rather than methods.

The other information, such as conversion rates, should be tied to Currency objects, rather than to individual transactions.

(Yes, I understand that there may need to be multiple Currency objects for the same national currency to reflect risk/date/usage/etc ... but even having a ThousandUSD Currency is better than attaching the formatting information separately to each line item.)