Hands-On Reactive Programming with Python

The do_action operator

The do_action operator allows us to execute a function each time an item is emitted on the source observable. This operator emits the same items as those received as input. The following figure shows the marble diagram of this operator:

Figure 9.18: The do_action operator

Its prototype is the following:

Observable.do_action(self,     on_next=None,     on_error=None,     on_completed=None,    observer=None)

Here, on_next, on_error, and on_completed are functions called each time the following occur:

• An item is received from the source observable
• An error is received from the source observable
• The source observable completes

The ...