What class to use for money representation?

Question

What class should I use for representation of money to avoid most rounding errors?

Should I use Decimal, or a simple built-in number?

Is there any existing Money class with support for currency conversion that I could use?

Any pitfalls that I should avoid?

Answer 1

You might be interested in QuantLib for working with finance.

It has built in classes for handling currency types and claims 4 years of active development.

Answer 2

You could have a look at this library: python-money. Since I've no experience with it I cannot comment on its usefullness.

A 'trick' you could employ to handle currency as integers:

• Multiply by 100 / Divide by 100 (e.g. $100,25 -> 10025) to have a representation in 'cents'

Answer 3

I assume that you talking about Python. http://code.google.com/p/python-money/ "Primitives for working with money and currencies in Python" - the title is self explanatory :)

Answer 4

Just use decimal.