Solving problems – currency conversion rates

The problem we have is that our informants are always asking for odd or unusual currencies. This isn't really all that surprising; we're dealing with spies and criminals on the run. They always seem to need obscure foreign currencies for their own nefarious projects.

We can get a big pile of international exchange rates using a piece of code like the following:

    query_exchange_rates= "http://www.coinbase.com/api/v1/currencies/exchange_rates/"

    with urllib.request.urlopen( query_exchange_rates ) as document:
        pprint.pprint( document.info().items() )
        exchange_rates= json.loads( document.read().decode("utf-8") )

The query string is a simple URL. When we make the request, we get back a long string of bytes. We decode this to make a proper string and use json.loads() to build a Python object.

The problem is that we get a giant dictionary object that's not really all that useful. It looks...