differences between event driven programming and reactive programming differences between event driven programming and reactive programming in event driven programmingan event is generated in response too something happeningthe event then represents this with any associated data for exampleif the user clicks the mouse then an associated mouseclickevent might be generated this object will usually hold information about the and coordinates of the mouse along with which button was clicked etc it is then possible to associate some behaviour (such as function or methodwith this event so that if the event occursthen the associated operation is invoked and the event object is provided as parameter this is certainly the approach used in the wxpython library presented earlier in this bookfrom the above diagramwhen moveevent is generated the on_move(method is called and the event is passed into the method in the reactive programming approachan observer is associated with an observable any data generated by the observable will be received and handled by the observer this is true whatever that data isas the observer is handler of data generated by the observable rather than handler of specific type of data (as with the event driven approachboth approaches could be used in many situations for examplewe could have scenario in which some data is to be processed whenever stock price changes this could be implemented using stockpricechangeevent associated with stockpriceeventhandler it could also be implemented via stock pricechangeobserverable and stockpricechangeobserver in either case one element handles the data generated by another element howeverthe rxpy library simplifies this process and allows the observer to run in the same thread asor separate thread fromthe observable with just small change to the code advantages of reactive programming there are several advantages to the use of reactive programming library these includeit avoids multiple callback methods the problems associated with the use of callbacks are sometimes referred to as callback hell this can occur when there are multiple callbacksall defined to run in response to some data being generated or some operation completing it can be hard to understandmaintain and debug such systems