How to add to dictionary if the value exists in python? [duplicate]

Question

I'm creating a dictionary from json data. I have a value 'actions' which is not on all the descriptions but I would like to add it to the ones that have it. How would I do it?

I tried to do it that way item['actions'] if item['actions'] else None but I'm still getting a keyerror with it.

 desc = {item['classid']: 
    [
        item['name'],
        item['market_hash_name'],
        item['icon_url'],
        item['tradable'],
        item['actions'] if item['actions'] else None
    ] for item in inventory['descriptions']}