Python学习_算数运算函数

grades = [100, 100, 90, 40, 80, 100, 85, 70, 90, 65, 90, 85, 50.5]#定义输出函数def PRint_grades(grades):    for grade in grades:        print grade#定义求和函数def grades_sum(grades):    total = 0    for grade in grades:         total += grade    return total#定义求平均值函数   def grades_average(grades):    sum_of_grades = grades_sum(grades)    average = sum_of_grades / float(len(grades))    return average#定义求方差函数def grades_variance(scores):    average=grades_average(scores)    variance=0    for score in scores:        variance+=(average-score)**2    return variance/len(scores)#定义求标准差函数    def grades_std_deviation(variance):    return variance**0.5    variance=grades_variance(grades)#调用函数分别输出对应的值print print_grades(grades)print grades_sum(grades)print grades_average(grades)print grades_variance(grades)print grades_std_deviation(variance)