Daniel Arbuckle's Mastering Python

The where factory method

While we could use select_many to remove unwanted events from an observable sequence, it's easier to use the where method. Let's look at the help information for the where method:

help (rx.Observable.where)  

This method applies a callable to each element of the input observable sequence and returns an observable sequence containing only those elements for which the callable returned true. The following image shows the help description:

Now we saw that there are fundamental ways to add and remove observable sequences, so what about processing them? We could just use select and select_many to do all of our processing, ...