What is the fastest method to check the difference between two json files in Python?
<p>So, I've a JSON file from which I get particular data by doing: </p>

<pre><code>user['screen']['username'],update['timestamp']
</code></pre>

<p>After, I call the file I get the JSON file in the same format but with new data. I want to check if I've got any new data. What I thought of doing is dumping this into a list and then doing a set difference between the old and the new list. I'm having problems regarding that at two places: 
      1. What is the fastest way to dump data into list comprehension? 
      2. Is that a good way to go about it(What is the point of dumping large amount of data when the change in data would be minimum?) </p>
