Python学习_算数运算函数

记录以grades列表为例，分别定义输出、求和、平均值、方差和标准差函数，并输出相应的值

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)

Python学习_算数运算函数