Hands-On Reactive Programming with Python

The switch_latest operator

The switch_latest operator take a higher-order observable as input. Each time a new item is emitted on this source observable, a subscription is done on the child observable, and the existing subscription on the previous item is disposed of. The following figure shows the marble diagram of this operator:

Figure 9.14: The switch_latest operator

Its prototype is the following:

Observable.switch_latest(self)

Here is an example of the switch_latest operator:

obs1 = Subject()obs2 = Subject()obs3 = Subject()higher_order = Subject()higher_order.switch_latest().subscribe( on_next = lambda i: print("on_next {}".format(i)), ...