Zero-decimal currencies support for Stripe

[pszpetkowski]

Some currencies (e.g. Japanese Yen) have smallest currency unit same as its primary currency unit and therefore do not have any decimal places. Most tools integrating Stripe assume that all currencies have SCU equal to 1/100 of PCU which in case of e.g. Japanese Yen is not true. I suppose that some currencies might even have SCU equal to 1/1000 or 1/10 of PCU.

How should we handle such cases? One solution that comes to my mind is to build a map of currencies compliant with ISO 4217 and one of keys providing SCU lambda.

For example:

CURRENCIES = {
    'USD': {
        'sign': '$',
        'scu': lambda: 1/100
    }
}

Also, should we fork / extend with PR existing lib like https://github.com/limist/py-moneyed or should we write something internal to DRP?

[pawelswiecki]

Looks good. Make sure lambdas return decimals.

[pawelswiecki]

About py-moneyed: I don't like forking idea. I'd prefer using it to get currency list and currency symbols.

BTW, it's not currency "sign", but "symbol": https://en.wikipedia.org/wiki/Currency_symbol.