app.py

from chalice import Chalice, Response

app = Chalice(app_name='hello-world')


@app.route('/books', methods=['GET', 'POST'])
def books_route():
    request = app.current_request

    if request.method == 'GET':
        return [
            dict(book_id=1),
            dict(book_id=2)
        ]
    elif request.method == 'POST':
        return Response(body=None,
                        headers=dict(Location='/books/3'),
                        status_code=201)


@app.route('/books/{book_id}', methods=['GET', 'PUT', 'DELETE'])
def books_route(book_id):
    request = app.current_request

    if request.method == 'GET':
        return get_book(book_id)
    elif request.method == 'PUT':
        return Response(body=None,
                        status_code=204)
    elif request.method == 'DELETE':
        return Response(body=None,
                        status_code=204)


def get_book(book_id):
    return dict(book_id=int(book_id))