我试图创建一个菜单驱动的程序，其中python将接受一组非负整数。它将计算平均值和中位数并在屏幕上显示值。我希望我的第一个选项是＆＃34;在列表/数组中添加一个数字＆＃34;，我希望我的第二个选项是＆＃34;显示平均值＆＃34;，第三个选项是＆＃34;显示中位数＆＃34;，第四个＆＃34;将列表/数组打印到屏幕＆＃34;，第五个＆＃34;以相反顺序打印列表/数组＆＃34;最后一个选项＆＃34; Quit＆＃34;。到目前为止，我已经得到了：
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(myList):
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...")
myList.append(num)
#This should take care of the second on the list: Mean
def mean(myList):
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(myList):
median = 0
sortedlist = sorted(myList)
lengthofthelist = len(sortedlist)
centerofthelist = lengthofthelist / 2
if len(sortedlist) % 2 ==0:
return sum(num[center - 1:center + 1]) / 2.0
else:
return num[center]
print("The mean is", centerofthelist)
#This will take care of the fourth thing on the list: Print the list (In order)
def sort(myList):
theList.sort(mylist)
print(myList)
#This will take care of the fifth thing on the list
def reversesort(myList):
theList.sort(reverse=True)
print(myList)
main()
运行程序后，我无法创建列表。
答案 0 :(得分：1)
def main():
myList = []
choice = 1
while choice != 6:
if choice == 1:
option1(myList)
elif choice == 2:
option2(myList)
elif choice == 3:
option3(myList)
elif choice == 4:
option4(myList)
elif choice == 5:
option5(myList)
choice = displayMenu()
print ("\nThanks for playing!\n\n")
def displayMenu():
myChoice = 0
while myChoice not in [1, 2, 3, 4, 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
5. Print the list/array in reverse order
6. Quit
""")
myChoice = int(input("Enter option---> "))
if myChoice not in [1, 2, 3, 4, 5]:
print("Invalid option. Please select again.")
return myChoice
# Option 1: Add a number to the list/array
def option1(myList):
num = -1
while num < 0:
num = int(input("\n\nEnter a non-negative integer: "))
if num < 0:
print("Invalid value. Please re-enter.")
myList.append(num)
# Option 2: Display the mean
def option2(myList):
print("The mean is ", sum(myList) / len(myList))
# Option 3: Display the median
def option3(myList):
sortedlist = sorted(myList)
if len(sortedlist) % 2:
median = myList[int(len(sortedlist) / 2)]
else:
center = int(len(sortedlist) / 2)
median = sum(myList[center-1:center+1]) / 2
print("The median is", median)
# Option 4: Print the list/array
def option4(myList):
print(sorted(myList))
# Option 5: Print the list/array in reverse order
def option5(myList):
print(sorted(myList, reverse=True))
main()
以下代码的第一部分是一组用于自定义菜单样式的常量。然后定义表示每个选项的一组函数。以下3个功能应该不进行修改，它们会生成菜单，显示它并关闭应用程序。然后主要部分开始，您需要将每个选项作为参数传递给setOptions（）。其余的应该不，因为它是主循环。
# Menu formatting constants
MENU_HEADER = "Please choose an option:"
MENU_FORMAT = " * {:2}. {}"
MENU_QUIT_S = "Quit"
MENU_ASK_IN = "Enter option: "
MENU_INT_ER = "ERROR: Invalid integer. Please select again."
MENU_OPT_ER = "ERROR: Invalid option. Please select again."
END_MESSAGE = "Thanks for playing!"
# OPTIONS FUNCTIONS START HERE
def addElement(l):
""" Add a number to the list/array. """
n = -1
while n < 0:
try:
n = int(input("Enter a non-negative integer: "))
except ValueError:
print("It needs to be an integer.")
n = -1
else:
if n < 0:
print("It needs to be a non-negative integer.")
l.append(n)
def mean(l):
""" Calculate the mean. """
print("Mean: {:7.2}".format(sum(l) / len(l)))
def median(l):
""" Calculate the median. """
l = sorted(l)
p = int(len(l) / 2)
print("Median: {:7.2}".format(l[p] if len(l)%2 else sum(l[p-1:p+1])/2))
def oprint(l):
""" Print the list/array. """
print(sorted(l))
def rprint(l):
""" Print the list/array in reverse order. """
print(sorted(l, reverse=True))
# OPTIONS FUNCTIONS END HERE
def onQuit(l):
""" Function to execute when quitting the application. """
global quit
quit = True
print(END_MESSAGE)
def setOptions(*args):
""" Generates the menu and the options list. """
# Menu header and quit option (option 0)
menu = [MENU_HEADER]
options = [onQuit]
# Passed arguments represent texts and functions of additional options
for i, f in enumerate(args, start=1):
menu.append(MENU_FORMAT.format(i, f.__doc__.strip()))
options.append(f)
# We print the option 0 the last one
menu.append(MENU_FORMAT.format(0, MENU_QUIT_S))
# Returning both the menu and the options lists
return tuple(menu), tuple(options)
def displayMenu(menu):
""" Display the menu and get an option that is an int. """
while True:
for line in menu:
print(line)
try:
choice = int(input(MENU_ASK_IN))
except ValueError:
print(MENU_INT_ER)
else:
return choice
if __name__ == '__main__':
# Pass the option functions to the setOptions function as arguments
menu, options = setOptions(
addElement,
mean,
median,
oprint,
rprint
)
# Initiate the needed variables and start the loop
l = []
quit = False
while not quit:
c = displayMenu(menu)
try:
f = options[c]
except IndexError:
print(MENU_OPT_ER)
else:
f(l)
答案 1 :(得分：0)
您的函数addOne中存在缩进错误。
myList.append(num)在while循环中，就在此之前你有一个break，所以这个数字永远不会附加到列表中，因为我们已经离开了循环。