Easier mapping of countries to currency

[mcarans]

Since you are using ISO2 country codes to get data from the IMF, you could use this mapping to get the 3 letter currency code from the ISO2 code: http://country.io/currency.json

[markbrough]

Apologies @mcarans, I only just discovered this issue! My first thought was whether this was updated recently enough -- the website says (c) 2014. It appears that the ISO Standard ISO 4217 was last updated in 2015, so maybe it could be OK.

However, I just checked and this version (which despite the strange URL is actually from the organisation responsible for maintaining this ISO Standard, states that it was last updated on 1st October 2021:
https://www.six-group.com/dam/download/financial-information/data-center/iso-currrency/lists/list_one.xml

So think this might require a bit more digging to work out what is best to use...

[markbrough]

NB the source origin file changed URL, it appears due to a website reorganisation.

The Last-Modified header for the currency.json file above is as follows:

Last-Modified: Wed, 03 Sep 2014 03:23:10 GMT

So I think we can't rely on that file exclusively, but perhaps we can look at it in line with #3