Default keys to be returned?

[michaelhelmick]

So right now, lassie will always return the keys image, video and url

{
    'images': [],
    'url': 'http://somesitethatdoesnthaveanythingbutexists.com',
    'videos': []
}

Does anything think that if images or videos are empty before the time to return a response, that those keys should be popped out of the dict?

[yaph]

I'd keep them with sensible default values, so the applications that import lassie can do a simple if check instead of calling get and then checking if the value evaluates to True.