iteration while print(nn print('blastoff!'you can almost read the while statement as if it were english it means"while is greater than display the value of and then reduce the value of by when you get to exit the while statement and display the word blastoff!more formallyhere is the flow of execution for while statement evaluate the conditionyielding true or false if the condition is falseexit the while statement and continue execution at the next statement if the condition is trueexecute the body and then go back to step this type of flow is called loop because the third step loops back around to the top we call each time we execute the body of the loop an iteration for the above loopwe would say"it had five iterations"which means that the body of the loop was executed five times the body of the loop should change the value of one or more variables so that eventually the condition becomes false and the loop terminates we call the variable that changes each time the loop executes and controls when the loop finishes the iteration variable if there is no iteration variablethe loop will repeat foreverresulting in an infinite loop infinite loops an endless source of amusement for programmers is the observation that the directions on shampoo"latherrinserepeat,are an infinite loop because there is no iteration variable telling you how many times to execute the loop in the case of countdownwe can prove that the loop terminates because we know that the value of is finiteand we can see that the value of gets smaller each time through the loopso eventually we have to get to other times loop is obviously infinite because it has no iteration variable at all sometimes you don' know it' time to end loop until you get half way through the body in that case you can write an infinite loop on purpose and then use the break statement to jump out of the loop this loop is obviously an infinite loop because the logical expression on the while statement is simply the logical constant truen while trueprint(nend=' print('done!'