Question

我已为编码编写此代码，但它无法正常工作。我希望我的程序在输入3个测试的名称和等级时验证3个用户的用户输入。我的程序只检查第一个输入，然后询问其他用户名，并跳过询问用户输入或验证输入。

validInput1 = False 
validInput2 = False 
validInput3 = False
studentnames = [] 
studentMarkTest1 = [] 
studentMarkTest2 = []
studentMarkTest3 = [] 
totalScores = [] 
sum = 0 
for i in range(3):
    sname = input("Enter Student name:")
    while not validInput1:
        score1 = int(input("What did {} get on their test 1?".format(sname)))
        if score1 < 0 or score1 >20:
          print("Invalid input")
        else:
          validInput1 = True
    while not validInput2:
        score2 = int(input("What did {} get on their test 2?".format(sname)))
        if score2 < 0 or score2 >25:
          print("Invalid input")
        else:
          validInput2 = True
    while not validInput3:
        score3 = int(input("What did {} get on their test 3?".format(sname)))
        if score3 < 0 or score3 >35:
          print("Invalid input")
        else:
          validInput3 = True
    totalScore = score1+ score2+ score3
    sum = sum + totalScore
    AverageTestScore = sum / 3
    # saving name and grade
    studentnames.append(sname)
    studentMarkTest1.append(score1)
    studentMarkTest2.append(score2)
    studentMarkTest3.append(score3)
    totalScores.append(totalScore) for i in range(3):
    print(studentnames[i],"total Test score",totalScores[i]) print("class average", AverageTestScore)

这里运行程序时会发生什么

>>> 
Enter Student name:g
What did g get on their test 1?44
Invalid input
What did g get on their test 1?33
Invalid input
What did g get on their test 1?44
Invalid input
What did g get on their test 1?22
Invalid input
What did g get on their test 1?20
What did g get on their test 2?34
Invalid input
What did g get on their test 2?23
What did g get on their test 3?55
Invalid input
What did g get on their test 3?44
Invalid input
What did g get on their test 3?32
Enter Student name:e
Enter Student name:e
g total Test score 75
e total Test score 75
e total Test score 75
class average 75.0
>>>

如何获得存储在totalscore中的最高测试分数值，然后使用得分最高的学生的姓名打印出最高分？

Answer 1

您需要在validInput循环之后将False放回while，或者更好地将其替换为for循环的开头。

Answer 2

让我们来看看你的while循环：

while not validInput1:

第一次运行应用程序时，validInput1为False，因此此块会进行评估。但是，在后续循环（来自for i in range(3):）上，validInput1已经为真，因此完全跳过此块。

您可以通过在for循环开头将validInput1，validInput2和validInput3更改为False来解决此问题。

Answer 3

这是因为validInput1，validInput2和validInput3变量在第一次迭代时设置为True，但在第二次迭代时未设置为false。

因此，对于第一次迭代后，由于＆＃34; not True＆＃34;即假

可以在每次迭代后再次将它们设置为false，即在循环结束时

Answer 4

当你有大量像这样的代码时很容易混淆......而是尝试将你的问题分成更小的部分

从一个函数开始，只获取一个学生的详细信息

def get_student_detail(num_tests): # get the detail for just 1 student!
    student_name = input("Enter Student Name:")
    scores = []
    for i in range(1,num_tests+1):
        scores.append(float(input("Enter Score on test %s:"%i)))
    return {'name':student_name,'scores':scores,'avg':sum(scores)/float(num_tests)}

现在只为每个学生打电话

student_1 = get_student_detail(num_tests=3)
student_2 = get_student_detail(num_tests=3)
student_3 = get_student_detail(num_tests=3)

print("Student 1:",student_1)
print("Student 2:",student_2)
print("Student 3:",student_3)

或者更好地实现一个让你可以随心所欲的功能

def get_students():
    resp="a"
    students = []
    while resp[0].lower() != "n":
        student = get_student_detail(num_tests=3)
        students.append(student)
        resp = input("Enter another students details?")
    return student

您可能希望拆分get_student_details甚至进一步编写方法以获得单个测试分数并验证其实际是一个数字（如果您输入的数字不是一个数字作为测试分数，这将会崩溃），或者在给出空响应之前继续询问测试分数等等

def get_number(prompt):
    while True:
         try: 
            return float(input(prompt))
         except ValueError:
            print ("That is not a valid number!")

def get_test_score(prompt):
    while True:
        score = get_number(prompt)
        if 0 <= score <= 100:
             return score
        print("Please enter a value between 1 and 100!")

test_score = get_test_score("Enter test score for test 1:")
print(test_score)

我的Python代码在错误的地方循环

4 个答案: