Hands-On Reactive Programming with Python

The timestamp operator

The timestamp operator adds a timestamp to each item emitted. The following figure shows the marble diagram of this operator:

Figure 9.23: The timestamp operator

Its prototype is the following:

Observable.timestamp(self, scheduler=None)

An alternative scheduler can be provided with the scheduler parameter. If no scheduler parameter is provided, then the timeout scheduler is used.

Here is an example of the timestamp scheduler:

numbers = Subject()numbers.timestamp().subscribe(    on_next = lambda i: print("on_next {}: {}".format(i.value, i.timestamp)),    on_error = lambda e: print("on_error: {}".format(e)), on_completed = lambda: ...