This format is known as JSON Lines: http://jsonlines.org/. Its support in the user code is trivial -- just one or two lines of code.

Writing:

    for item in items:
        json.dump(item, file)

or

    jsondata = ''.join(json.dumps(item) for item in items)

Reading:

    items = [json.loads(line) for line in file]

or

    items = [json.loads(line) for line in jsondata.splitlines()]

See also issue31553 and issue34393. I think all these propositions should be rejected.