Seite - 91 - in Programming for Computations – Python - A Gentle Introduction to Numerical Simulations with Python 3.6, Band Second Edition

4.2 ProgrammingasaStep-WiseStrategy 91 return 1 without actually testing anything. In this way, we will be able to run the program,while still havingunfinishedparts in there. We have introducedN as a variable here to allow easy adjustment of “problem size” (the total number of questions will beN*N). We knowNmust be 10, but that requirementapplies to the finalversiononly.Thus,we are free to doour steps with a smallerN, and that makes life much easier for us when assessing code behavior. If you have not already done so, go through the code by hand to confirm that you understandwhathappens, in whatorder. Whenexecuted, theprogramsimplyprints: *** Welcome to the times tables test! *** (To stop: ctrl-c) 1*1 = 1*1 = 1 Your score is now: 1 1*2 = 1*2 = 2 Your score is now: 2 2*1 = 2*1 = 2 Your score is now: 3 2*2 = 2*2 = 4 Your score is now: 4 Finished! Your final score: 4 (max: 4) From the printout,we see that the two functionsseem to get the right arguments in eachcall.We are thus readyfor thenextstep, i.e., to implement the functionbodies of the twofunctions. 4.2.3 The2ndVersionofOurCode After implementing the remaining parts of the code, we have a version (times_tables_2.py) of our program that actually does the testing that was asked for.Thecode reads def ask_user(a, b): """get answer from user: a*b = ?""" question = ’{:d} * {:d} = ’.format(a, b) answer = int(input(question)) return answer def points(a, b, answer_given): """Check answer. Correct: 1 point, else 0""" true_answer = a*b if answer_given == true_answer: print(’Correct!’) return 1 else: print(’Sorry! Correct answer was: {:d}’.format(true_answer)) return 0