Keys in dict and keys not in dict

Sun Mar 18 23:41:05 EDT 2018

On Mon, Mar 19, 2018 at 2:32 PM, Andrew Z <formisc at gmail.com> wrote:
> hello,
>> i'd like to check if a function parameter (json) has all the keys I expect
> it to have and if it doesn't - point out the one that is missing.
>> What's the good way of doing that?
>> "good way" - something concise... i'd like to avoid using :
> if key in json:
> #pass
> else
> print(" Oops, i did it again ...")

Sounds like a set operation to me.
expected = {"foo", "bar", "spam"}
missing = expected - set(json)
if missing:
 print("Missing keys:", missing)
ChrisA