Hands-On Reactive Programming with Python

Always specify a scheduler

When using an AsyncIO event loop, it is very important to schedule items explicitly from the AsyncIO scheduler. Otherwise, depending on the way the operator chain is built, items may be emitted before the event loop is started (especially with observable cycles). This might lead to situations where items are lost, because they have been emitted before one of its observers subscribed to the associated observable. This is another possible reason why nothing happens when the application starts.