python入门利器-codecademy-分享一个简单练习

#字典的定义方式
lloyd = {
    "name": "Lloyd",
    "homework": [90.0,97.0,75.0,92.0],
    "quizzes": [88.0,40.0,94.0],
    "tests": [75.0,90.0]
}
alice = {
    "name": "Alice",
    "homework": [100.0, 92.0, 98.0, 100.0],
    "quizzes": [82.0, 83.0, 91.0],
    "tests": [89.0, 97.0]
}
tyler = {
    "name": "Tyler",
    "homework": [0.0, 87.0, 75.0, 22.0],
    "quizzes": [0.0, 75.0, 78.0],
    "tests": [100.0, 100.0]
}
 若要打印学生的名称及其成绩：
students=[lloyd,alice,tyler]
for each in students:
    print each["name"]
    print each["homework"]
    print each["quizzes"]
    print each["tests"]
Lloyd
[90.0, 97.0, 75.0, 92.0]
[88.0, 40.0, 94.0]
[75.0, 90.0]
Alice
[100.0, 92.0, 98.0, 100.0]
[82.0, 83.0, 91.0]
[89.0, 97.0]
Tyler
[0.0, 87.0, 75.0, 22.0]
[0.0, 75.0, 78.0]
[100.0, 100.0]


# 自定义一个函数求一个list的平均值
def average(numbers):
    total=sum(numbers)
    total=float(total)
    return total/len(numbers)

#自定义一个函数，求一个学生的综合成绩，先求出各个分类的平均成绩，再分别乘以每个类别的权重，得到他的综合成绩
def get_average(student):
    homework=average(student["homework"])
    quizzes=average(student["quizzes"])
    tests=average(student["tests"])
    return 0.1*homework+0.3*quizzes+0.6*tests

#自定义一个函数，将成绩分为不同等级
def get_letter_grade(score):
    if score>=90:
        return "A"
    elif score>=80 and score<90:
        return "B"
    elif score>=70 and score<80:
        return "C"
    elif score>=60 and score<70:
        return "D"
    else:
        return "F"

#测试一下，求Lloyd的综合成绩
get_letter_grade(get_average(lloyd))

#定义一个函数，求一个班级的综合成绩
def get_class_average(students):
    results=[];
    for student in students:    
        results.append(get_average(student))
    return average(results)

#假设这个班有三个人
print get_class_average([lloyd,alice,tyler])

print get_letter_grade(get_class_average([lloyd,alice,tyler]))