chaining operators for examplewe might first start off by filtering the output from an observable such that only certain data items are published we might then apply transformation in the form of map(operator to that dataas shown belownote the the order in which we have applied the operatorswe first filter out data that is not of interest and then apply the transformation this is more efficient than apply the operators the other way around as in the above example we do not need to transform the odd values it is therefore common to try and push the filter operators as high up the chain as possible the code used to generate the chained set of operators is given below in this case we have used lambda functions to define the filter(function and the map (function the operators are applied to the observable obtained from the list supplied the data stream generated by the observable is processed by each of the operators defined in the pipe as there are now two operators the pipe contains both operators and acts pipe down which the data flows the list used as the initial source of the observables data contains sequence of event and odd numbers the filter(function selects only even numbers and the map(function transforms the integer values into strings we then subscribe an observer function to the observable produced by the transformational map(operator example of chaining operators together import rx from rx import operators as op set up source with filter source rx from_list([ ]pipe source pipeop filter(lambda valuevalue = )op map(lambda value"'str(value"'"subscribe lambda function pipe subscribe(lambda valueprint('received'value)