Example of a convenient way to stream generators as JSON in your flask app

flask_stream_generators.py

import json

from flask import Response, stream_with_context


def render_as_json(generator_creating_function):
    """ Decorator to render JSON from generator-creating functions
    """
    
    def wrapper():
        generated_items = generator_creating_function()
        yield '{"items":['
        try:
            while True:
                first = json.dumps(next(generated_items))
                second = json.dumps(next(generated_items))
                yield ','.join([first, second]) + ','
        except StopIteration:
            yield first
        yield ']}'

    return wrapper

  
@render_as_json
def create_generator():
    """ Fill this with something that yields items or returns a generator
    """
    pass
    
    
@app.route('/stream-generator', methods=['GET'])
def stream_generator():
    return Response(stream_with_context(create_generator()), 200, mimetype='application/json')