正整数和、平均值、计数

Question

我的编程教授要求我创建一个程序，该程序要求用户输入他们愿意输入的正整数（包括零）。除正整数之外的任何内容都会停止输入并计算/显示数字的总和、平均值和计数。

我遇到的主要问题与返回多个要在程序中传递的正整数有关。我似乎找不到我需要的东西。

inputPostiveInteger()

Pass in nothing
Ask the user for a positive integer
Return the integer is the user inputs one
Return -1 if the user does not input a positive integer

他让程序工作的方式就是例子-

Enter a positive integer, anything else to quit: 1
Enter a positive integer, anything else to quit: 5
Enter a positive integer, anything else to quit: 10
Enter a positive integer, anything else to quit: cat
Sum 16
Average 5.3
Total numbers 3

我尝试了多种方式的 try/except 和 while not 子句来获得正确的输入部分，但似乎无法将我的大脑包裹在这一点上。

我了解如何计算/显示平均值、计数、总和的公式 - 但似乎无法在多个公式中获得经过审查的整数条目。

例如。用于尝试输入

def inputPositiveInteger():
    try:
        userInt = int(input("Enter a positive integer, anything else to quit: ")) > -1
    except ValueError:
        return -1

def main():
    total = 0
    count = 0
    posInt = inputPositiveInteger()
    while posInt != -1:
        total += posInt
        count += 1

main()

---

total = 0
userInt = int(input('Enter a positive integer, anything else to quit: '))

while userNumber > -1:
    total += userInt
    userInt = int(input('Enter a positive integer, anything else to quit: '))

Answer 1

我试着让我的解决方案有点像你的代码：

def inputPositiveInteger():
    try:
        userInt = int(input("Enter a positive integer, anything else to quit: "))
    except ValueError:
        return -1

    if userInt < 0:
        return -1
    return userInt

def main():
    total = 0
    count = 0
    posInt = inputPositiveInteger()
    while posInt != -1:
        total += posInt
        count += 1
        posInt = inputPositiveInteger()

    if count == 0:
        print("Sum:", None)
        print("Average:", None)
        print("Total numbers:", None)
    else:
        print("Sum:", total)
        print("Average:", total/count)
        print("Total numbers:", count)

main()

此外，您可能已经或可能没有涵盖数组（又名列表），在我看来这将是可行的方法，这里也没有尝试，除非必要：

def inputPositiveInteger():
    userInt = input("Enter a positive integer, anything else to quit: ")
    # str.isnumeric checks that a string only contains numbers and isn't empty
    if not userInt.isnumeric():
        return -1
    return int(userInt)

def main():
    posInt = inputPositiveInteger()
    nums = []
    while posInt != -1:
        nums.append(posInt)
        posInt = inputPositiveInteger()

    if nums:
        print("Sum:", sum(nums))
        print("Average:", sum(nums)/len(nums))
        print("Total numbers:", len(nums))
    else:
        print("Sum:", None)
        print("Average:", None)
        print("Total numbers:", None)

main()

希望这会有所帮助，祝你的课好运。

Answer 2

试试这个：

def finish(summ,count):
    print('Sum',summ)
    print('Count',count)
    print('Avg',round(summ/count,5))

summ = 0
count = 0
while True:
    try:
        userInt = int(input('Enter a positive integer, anything else to quit: '))
        if userInt >= 0:
            summ += userInt
            count += 1 
        else:
            finish(summ,count)
            break
    except:
        finish(summ,count)
        break

Answer 3

感谢您缩小输入范围的建议，我最终将其作为最终提交的代码。

def calcAverage(total, count):
    return round(float(total) / float(count), 2)

# prompt user to enter posInt
def inputPositiveInteger():
    userInt = input("Enter a positive integer, anything else to quit: ")
    # return input if digit, else return -1
    if not userInt.isdigit():
        return -1
    return int(userInt)

def main():
    # call function
    posInt = inputPositiveInteger()
    nums = []
    while posInt != -1:
        nums.append(posInt)
        posInt = inputPositiveInteger()

    if nums:
        print("Sum", sum(nums))
        print("Average", calcAverage(sum(nums), len(nums)))
        print("Total numbers", len(nums))


main()