A Pyramid tween (contraction of between) is a bit like a piece of middleware. They allow you to act upon a request or response before/after hitting the controller in a context where they have access to the request, response and app registry.
They comprise of a factory and the function that does the work, e.g in a file called tweens/example_tween:
def example_tween_factory(handler, registry): def example_tween(request): response = handler(request) return response return example_tween
Which are then registered in the main function:
This short series will detail tweens that I’ve used in projects and found useful.