I'm not sure if I understand this correctly. I've written the following bit of simple code:
for portfolio in portfolios:
symbol = portfolio["symbol"]
look = lookup(symbol)
price = float(look["price"])
However, sometimes, usually, when reloading the page it gives me the error that look"["price"] -- 'NoneType' object is not subscriptable.
I assume it returns the lookup, but not the price elements.
It would do so if it cannot lookup the symbol. In that case, lookup returns None, a special value of type NoneType indicating absense of something, like proper data.
Since you are looping a list portfolios, I assume those are symbols of stocks already bought, so they should exist.
That seems a frequent problem currently, the API sometimes not returning the expected data, implementing some kind of cache might help (to reduce the number of requests, or re-use an old response if the request fails). I'm not sure the average student is expected to write such thing.
As far as I know, the check50 and submit50 checkers do not rely on those external services, and inject their own lookup (to test your code in certain situations, like whether you render a money value with trailing zeroes like $42.00 correctly). So if you are sure your code is right, even though it sometimes fails for this None response, you might still be able to submit.
