JSON isn't a database:
That's not a database, dude![
^]
To "merge" JSON files, they all need to be using the same data structure (not guaranteed) and require you to either load the JSON data into python classes and merge those before generating a new JSON string from the result, or write your own JSON parser to read the content of each file and process it into data you can understand yourself.
There is no "search json files" code because JSON files aren't a database!