I'm a student learning Python, I made this calculator that will tell you the tuition for the next 5 years at an increase of 3% per year. How can I improve on this and did I do anything that isn't best practice? RESIDENCY_COST = { "I": 10000, "O": 24000, "G": 40000, } cost_of_tuition = None while True: residency = raw_input('Please input your type of residency, I for in-state, O for out-of-state, and G for graduate: ') try: cost_of_tuition = RESIDENCY_COST[residency] break except ValueError: print ('Please enter I, G or O ONLY.') years = [] tuition_increase = [] academic_year = [] academic_year_inc = [] for _ in range(5): intMath = cost_of_tuition * 0.03 tuition_increase.append(intMath) fnlMath = intMath + cost_of_tuition years.append(fnlMath) cost_of_tuition = fnlMath academic_year.append("${:,.2f}".format(fnlMath)) academic_year_inc.append("${:,.2f}".format(intMath)) total_tuition_increaseSum = sum(tuition_increase) total_tuition_increase = "${:,.2f}".format(total_tuition_increaseSum) print('UNDERGRADUATE TUITION FOR THE NEXT FIVE YEARS ') print('ACADEMIC YEAR TUITION INCREASE ') print('------------- ------------ -------- ') for i, year in enumerate(range(16, 21)): print('{}-{} {} {}'.format(year + 2000, year + 1, academic_year[i], academic_year_inc[i])) print('TOTAL TUITION INCREASE ' + total_tuition_increase)