Hands-On Reactive Programming with Python

The average operator

The average operator computes the average value of all items emitted on the source observable. The following figure shows the marble diagram of this operator:

Figure 9.35: The average operator

Its prototype is the following:

Observable.average(self, key_selector=None)

Here, the key_selector argument is a transform function that returns the value to average from an item. If no key_selector is provided, then the item itself is used.

Here is an example of the average operator:

numbers = Observable.from_([1, 2, 3, 4])numbers1.average().subscribe(    on_next = lambda i: print("on_next {}".format(i)), on_error = lambda e: print("on_error: ...