wasn' matched by specific if or elif testand that can sometimes include invalid or even malicious data if you have specific final condition you are testing forconsider using final elif block and omit the else block as resultyou'll gain extra confidence that your code will run only under the correct conditions testing multiple conditions the ifelifelse chain is powerfulbut it' only appropriate to use when you just need one test to pass as soon as python finds one test that passesit skips the rest of the tests this behavior is beneficialbecause it' efficient and allows you to test for one specific condition howeversometimes it' important to check all of the conditions of interest in this caseyou should use series of simple if statements with no elif or else blocks this technique makes sense when more than one condition could be trueand you want to act on every condition that is true let' reconsider the pizzeria example if someone requests two-topping pizzayou'll need to be sure to include both toppings on their pizzatoppings py requested_toppings ['mushrooms''extra cheese' if 'mushroomsin requested_toppingsprint("adding mushrooms " if 'pepperoniin requested_toppingsprint("adding pepperoni " if 'extra cheesein requested_toppingsprint("adding extra cheese "print("\nfinished making your pizza!"we start at with list containing the requested toppings the if statement at checks to see whether the person requested mushrooms on their pizza if soa message is printed confirming that topping the test for pepperoni at is another simple if statementnot an elif or else statementso this test is run regardless of whether the previous test passed or not the code at checks whether extra cheese was requested regardless of the results from the first two tests these three independent tests are executed every time this program is run because every condition in this example is evaluatedboth mushrooms and extra cheese are added to the pizzaadding mushrooms adding extra cheese finished making your pizzaif statements