在Python中创建一个for循环来检查列表值

Question

我的家庭作业有问题。我需要创建一个 for 循环来计算某个值在列表中出现的次数。这是代码：

def get_test_scores():

    tests = []

    for i in range(SIZE):

        test_score = int(input("Enter test score #"+str(i+1)+" in the range 0-100: "))

        while (test_score <0) or (test_score >100):

            print("ERROR!")

            test_score = int(input("Enter test score #"+str(i+1)+" in the range 0-100: "))        

    tests.append(test_score)    

    return tests

def find_perfect(tests):

    count = 0

    for test_score in tests:

        if test_score == 100:

            count += 1

    return count

我无法获得计数值来反映我输入了多少个 100

Answer 1

当您处理此类事情（无论是作业还是生产代码）时，最好测试每个单独的函数以确保它们正常工作。例如，尝试find_perfect使用不同的（硬编码的）列表运行；你会发现它每次都能得到正确的答案。现在尝试测试get_test_scores并打印输出。哎呀！您的问题是您仅附加最后的测试分数。该线tests.append(test_score)应该位于for循环内部。

Answer 2

你tests.append(test_score)会发生一次，因为它在 for 循环之外，试试这个：def get_test_scores():&nbsp; &nbsp; tests = []&nbsp; &nbsp; for i in range(SIZE):&nbsp; &nbsp; &nbsp; &nbsp; test_score = int(input("Enter test score #"+str(i+1)+" in the range 0-100: "))&nbsp; &nbsp; &nbsp; &nbsp; while (test_score <0) or (test_score >100):&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; print("ERROR!")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; test_score = int(input("Enter test score #"+str(i+1)+" in the range 0-100: "))&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; tests.append(test_score)&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; return tests顺便说一句，我认为值得快速计算你有多少个 100 并且不再迭代，在 python 中，你可以从像 tuple 这样的函数返回很少的值，例如：def get_test_scores():&nbsp; &nbsp; tests = []&nbsp; &nbsp; count = 0&nbsp; &nbsp; for i in range(SIZE):&nbsp; &nbsp; &nbsp; &nbsp; test_score = int(input("Enter test score #"+str(i+1)+" in the range 0-100: "))&nbsp; &nbsp; &nbsp; &nbsp; while (test_score <0) or (test_score >100):&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; print("ERROR!")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; test_score = int(input("Enter test score #"+str(i+1)+" in the range 0-100: "))&nbsp; &nbsp; &nbsp; &nbsp; if test_score == 100:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; count += 1&nbsp; &nbsp; &nbsp; &nbsp; tests.append(test_score)&nbsp; &nbsp;&nbsp;&nbsp; &nbsp; return count, tests用法 ：count, scores = get_test_scores()count 是一个数字，scores 是分数列表

Answer 3

tests.append(test_score)通过在 for 循环之前添加 tab 来使其内部