Question

问题

我正在制作一个可以告诉你成绩的课程。我已经获得了所有用户输入，现在我需要做一些计算。调用calculate_weighted_average时出现问题。它将参数作为整数（至少我认为它是这样的：我问它print(x, y, z)并且它打印两次，一次作为x，y，z的正确输入，一次作为x的正确输入但它打印y和z为无）但它拒绝做我要求它做的数学运算。该功能是否能够接受参数并执行以下简单操作：( x + y ) * z？
所以由于某种原因，y和z变为None，这是我需要解决的问题！

守则

def main():
    tests = get_initial_input("tests")
    assignments = get_initial_input("assignments")
    exercises = get_initial_input("exercises")
    labs = get_initial_input("labs")
    finals = get_initial_input("finals")
    testsp = get_percents(tests , "tests")
    assignmentsp = get_percents(assignments, "assignments")
    exercisesp = get_percents(exercises, "exercises")
    labsp = get_percents(labs, "labs")
    finalsp = get_percents(finals, "finals")
    testst = get_totals(tests, "tests")
    assignmentst = get_totals(assignments, "assignments")
    exercisest = get_totals(exercises, "exercises")
    labst = get_totals(labs, "labs")
    finalst = get_totals(finals, "finals")
    testss = get_scores(tests, "tests")
    assignmentss = get_scores(assignments, "assignments")
    exercisess = get_scores(exercises, "exercises")
    labss = get_scores(labs, "labs")
    finalss = get_scores(finals, "finals")
    testsz = calculate_weighted_average(testss, testst, testsp)
    assignmentsz = calculate_weighted_average(assignmentss, assignmentst, assignmentsp)
    exercisesz = calculate_weighted_average(exercisess, exercisest, exercisesp)
    labsz = calculate_weighted_average(labss, labst, labsp)
    finalsz = calculate_weighted_average(finalss, finalst, finalsp)
def get_initial_input(x):
    val = int(input("How many "+ x + " were there?    "))
    return val

def get_percents(x, string):
    if x > 0:
            xp = int(input("What percentage are "+ string + " weighted?       "))
            return xp

def get_totals(x, string):
    if x > 0:
            xt = int(input("How many total points available in the "+ string +" category?      "))
            return xt

def get_scores(x, string):
    total = 0
    for y in range(x):
            xs = int(input("Scores for "+ string +" ?:     "))
            total = total + xs
    return total
def calculate_weighted_average(x, y, z):
    print(x, y, z)
    this = ( x / y ) * z
    return this

main()

追溯

How many tests were there?    2
How many assignments were there?    0
How many exercises were there?    0
How many labs were there?    0
How many finals were there?    0
What percentage are tests weighted?       20
How many total points available in the tests category?      20
Scores for tests ?:     20
Scores for tests ?:     20
40 20 20
0 None None
Traceback (most recent call last):
  File "assignment7.py", line 61, in <module>
    main()
  File "assignment7.py", line 23, in main
    assignmentsz = calculate_weighted_average(assignmentss, assignmentst, assignmentsp)
  File "assignment7.py", line 49, in calculate_weighted_average
    this = ( x / y ) * z
TypeError: unsupported operand type(s) for /: 'int' and 'NoneType'

提前谢谢

Answer 1

即使条件失败，您也需要调整get_totals和get_percents以返回int。如果不满足其中任何一个条件，将返回None。

例如：

def get_percents(x, string):
    xp = 0
    if x > 0:
        xp = int(input("What percentage are "+ string + " weighted?       "))
    return xp

此外：

def get_totals(x, string):
    xt = 0
    if x > 0:
        xt = int(input("How many total points available in the "+ string +" category?      "))
    return xt

Answer 2

功能

def get_totals(x, string):
  if x > 0:
        xt = int(input("How many total points available in the "+ string +" category?      "))
        return xt

当None小于或等于零时，

返回x。此值稍后传播到calculate_weighted_average中的数值表达式并将其分解。修复此函数和其他函数以始终返回数字或抛出异常。

Python - TypeError：/：＆＃39; int＆＃39;不支持的操作数类型和＆＃39; NoneType＆＃39;

2 个答案: