Python中的菜单列表

我对Python非常陌生，所以我提前道歉！我正在尝试创建一个列表，其中用户可以选择添加数字、显示平均值、显示中值、按顺序打印列表、按相反顺序打印列表或退出。我以为我在正确的轨道上，但我不能让它运行。有人能帮我吗

def main():
    myList = [ ]
    addOne(myList)
    choice = displayMenu()
    while choice != '6':
        if choice == '1':
            addOne(myList)
        elif choice == '2':
            mean(myList)
        elif choice == '3':
            median(myList)
        elif choice == '4':
             print(myList)
        elif choice == '5':
            print(myList)
        choice = displayMenu()

    print ("\nThanks for playing!\n\n")

def displayMenu():
    myChoice = '0'
    while myChoice != '1' and myChoice != '2' \
              and myChoice != '3' \
              and myChoice != '4' and myChoice != '5':
        print("""\n\nPlease choose
                1. Add a number to the list/array
                2. Display the mean
                3. Display the median
                4. Print the list/array to the screen
                5. Print the list/array in reverse order
                6. Quit
                """)
        myChoice = input("Enter option---> ")
        if myChoice != '1' and myChoice != '2' and \
           myChoice != '3' and myChoice != '4' and myChoice != '5':
            print("Invalid option. Please select again.")

    return myChoice

#This should make sure that the user puts in a correct input
def getNum():
    num = -1
    while num < 0:
        num = int(input("\n\nEnter a non-negative integer: "))
        if num < 0:
            print("Invalid value. Please re-enter.")

    return num

#This is to take care of number one on the list: Add number
def addOne(theList):
    while True:
        try:
            num = (int(input("Give me a number:")))
            num = int(num)
            if num < 0:
                raise exception
            print("Thank you!")
            break
        except:
            print("Invalid. Try again...")
        theList.append(num)


#This should take care of the second on the list: Mean       
def mean(theList):
    myList = []
    listSum = sum(myList)
    listLength = len(myList)
    listMean = listSum / listLength
    print("The mean is", listMean)

#This will take care of number three on the list: Median
def median(theList):
    myList = []
    return myList.median(theList.array(myList))
    print("The median is", listMedian)


#This will take care of the fourth thing on the list: Print the list 
def sort(theList):
    theList.sort()
    print(theList) 

#This will take care of the fifth thing on the list
def reversesort(theList):
    theList.sort(reverse=True)
    print(theList)


main()  

当我尝试选择选项2时，它会给我：

Traceback (most recent call last):
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception        Handling.py", line 94, in <module>
    main()
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception   Handling.py", line 12, in main
    mean(myList)
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception   Handling.py", line 73, in mean
    listMean = listSum / listLength
ZeroDivisionError: division by zero

Traceback (most recent call last):
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception  Handling.py", line 94, in <module>
    main()
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception Handling.py", line 14, in main
    median(myList)
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception Handling.py", line 79, in median
    return myList.median(theList.array(myList))
AttributeError: 'list' object has no attribute 'median'

当我尝试运行第三个选项时，它会给我：

Traceback (most recent call last):
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception        Handling.py", line 94, in <module>
    main()
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception   Handling.py", line 12, in main
    mean(myList)
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception   Handling.py", line 73, in mean
    listMean = listSum / listLength
ZeroDivisionError: division by zero

Traceback (most recent call last):
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception  Handling.py", line 94, in <module>
    main()
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception Handling.py", line 14, in main
    median(myList)
  File "/Users/Gunter/Documents/CS 110/List and Traversal and Exception Handling.py", line 79, in median
    return myList.median(theList.array(myList))
AttributeError: 'list' object has no attribute 'median'

均值问题 您从回溯消息中得到了一个非常好的提示：ZeroDivisionError:DivisionbyZero。你们部门的分母是什么？列表长度。listLength是从哪里计算的？使用函数的本地作用域创建的空列表myList的长度。您需要将列表的长度作为参数传递给函数

你的平均数计算还有另一个问题：你的分子对除法也不正确。修复它是留给您的一项练习

中位数问题 同样，回溯消息给了您一个非常好的提示：AttributeError:'list'对象没有属性'median'。和均未提供中值方法。您需要将其定义为函数，或者构建一个类，将其定义为类方法，并将列表作为内部存储

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或者，您可以避免重新发明轮子——这可能是所有答案中最具python风格的一个——并使用标准库中的模块。

您需要更具体一些，而不是我无法让它运行。我已经尝试过复制/粘贴它，但有一些东西尚未定义。你有什么问题？这应该是一个独立的例子吗？如果我试图选择计算平均值或计算中位数，它就会爆炸。如果我尝试选择按顺序或反向打印列表，它只会显示一个空集。如果代码崩溃，它通常会在回溯中提供一个方便的错误线索。你能把它作为一个编辑包含在你的问题中吗？甚至没有运行代码，我的编辑器将listMedian显示为未定义的中间值，因此我知道它将无法运行。我只是在尝试运行平均值和中间值时发布了它所说的内容。谢谢你帮助我！