如果用户没有输入某个单词则打印一条错误消息
Printing an error message if a user does not input a certain word
这有点像我之前问过的问题，但有点不同。
我是一名编程初学者（以前从未编程过），我接到了一项任务（在学校）制作一个程序，要求用户提供一个或多个形状，然后根据给定的尺寸计算该形状的体积由用户。然而，如果用户不输入 "quit"，程序应该继续询问用户形状并继续计算体积，当用户输入 "quit" 时，程序应该会打印出来计算的体积列表。三种形状分别是立方体、金字塔和椭圆体。
例如，如果用户输入立方体、立方体、金字塔、金字塔、椭圆体然后退出（连同计算体积所需的尺寸），则程序应打印出：
立方体积：4、5
金字塔体积：6、7
椭圆体积：8
注意：这些数字仅供参考。
我已经成功（有点）让程序注意到错误，并让程序反复询问用户形状和计算体积，直到输入 "quit"。但是，如果用户没有输入 cube 例如，那么最终的输出应该是：
多维数据集体积：您尚未对多维数据集进行任何计算
金字塔体积：6、7
椭圆体积：8
而不是我现在得到的是：
立方体体积：[]
金字塔体积：6、7
椭圆体积：8
有什么方法可以实现正确的最终输出吗？
这是我的代码（它可能不是那么好，但这是我作为初学者和目前所学知识所能做到的最好的）：
#A program that allows the user to continuously pick different shapes and calculate their volumes.
#import all functions from the math module.
import math
#allows the user to input the shape they want to calculate the volume of. Then that input is converted to all upper case
#letters so that no matter what the user enters, it will be recognizable by the program.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
#Initializing the lists for the volumes of the three different shapes as empty lists so that it can be filled
#later on.
VolumeListCube = []
VolumeListPyramid =[]
VolumeListEllipsoid = []
#defining the function that will calculate the volume of the cube and then adding them to the empty list VolumeListCube.
def VolumeCube (sideLength):
volume = sideLength**3
#Adding the values to the list
VolumeListCube.append(volume)
#Sorting the values in the created list in ascending order
VolumeListCube.sort()
return;
#defining the function that will calculate the volume of the pyramid and then adding them to the empty list VolumeListPyramid.
def VolumePyramid (baseLength, height):
volume = round((1/3)*(baseLength**2)*height,1)
#Adding the values to the list
VolumeListPyramid.append(volume)
#Sorting the values in the created list in ascending order
VolumeListPyramid.sort()
return;
#defining the function that will calculate the volume of the ellipsoid and then adding them to the empty list VolumeListEllipsoid.
def VolumeEllipsoid (radius1, radius2, radius3):
volume = round((4/3)*math.pi*radius1*radius2*radius3,1)
#Adding the values to the list
VolumeListEllipsoid.append(volume)
#Sorting the values in the created list in ascending order
VolumeListEllipsoid.sort()
return;
#The first while loop here checks if the user immediately inputs "Quit" or not, if they don't, then the next while loop is
#executed, if they do input "Quit", then the program will print the require message.
while shape != "QUIT":
#This is a infinte while loop since true is always true, this allows the error message at the end to be displayed
#and then loop back to the beginning of this loop, so that it can be executed again.
while True:
if shape in ["CUBE","PYRAMID","ELLIPSOID","QUIT"]:
#These if functions will allow the user to input shape parameters depending on what shape the user has chosen, then
#afterwards, another prompt is show for the user to choose another shape and input that shape's parameters. This will
#continue until the user inputs "Quit", then the required message will be printed and the volume results fot all the
#shapes chosen will be displayed in ascending order.
if shape == "CUBE":
sideLength = int(input("Please enter the length of the sides of the cube:"))
#recalling the function that calculates the volume of the cube.
VolumeCube (sideLength)
#lets the user to input another shape they want to calculate the volume of.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
elif shape == "PYRAMID":
baseLength = int(input("Please enter the base length:"))
height = int(input("Please enter the height:"))
# recalling the function that calculates the volume of the pyramid.
VolumePyramid (baseLength, height)
#lets the user to input another shape they want to calculate the volume of.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
elif shape == "ELLIPSOID":
radius1 = int(input("Please enter the first radius:"))
radius2 = int(input("Please enter the second radius:"))
radius3 = int(input("Please enter the third radius:"))
# recalling the function that calculates the volume of the ellipsoid.
VolumeEllipsoid (radius1, radius2, radius3)
#lets the user to input another shape they want to calculate the volume of.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
elif shape == "QUIT":
print ("\nYou have come to the end of the session.\nthe volume calculated for each shape are shown below:\n")
print("The volume of the cube(s) is:", VolumeListCube)
print("The volume of the pyramid(s) is:", VolumeListPyramid)
print("The volume of the ellipsoid(s) is:", VolumeListEllipsoid)
#This exits the program to stop repeated prints that would be caused due to the while loop
exit()
else:
print("Error, please enter a valid shape")
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
else:
print ("\nYou have come to the end of the session.\nYou have not performed any volume calculations")
TL;DR
没有时间查看您的代码，但我猜您得到的最终结果是 list，因此
cube volumes: []
对此的快速逃避是使用 if 语句来检查列表的大小是否为 0。即，用户没有给出 shape.
所以，一个简单的：
print('cube volumes:',end=' ')
#VolumeListCube is holding the final results
if len(VolumeListCube) == 0:
print("You have not done any calculations for the cube")
else :
#print your values as usual
应该足够了。
这有点像我之前问过的问题，但有点不同。
我是一名编程初学者（以前从未编程过），我接到了一项任务（在学校）制作一个程序，要求用户提供一个或多个形状，然后根据给定的尺寸计算该形状的体积由用户。然而，如果用户不输入 "quit"，程序应该继续询问用户形状并继续计算体积，当用户输入 "quit" 时，程序应该会打印出来计算的体积列表。三种形状分别是立方体、金字塔和椭圆体。
例如，如果用户输入立方体、立方体、金字塔、金字塔、椭圆体然后退出（连同计算体积所需的尺寸），则程序应打印出：
立方体积：4、5
金字塔体积：6、7
椭圆体积：8
注意：这些数字仅供参考。
我已经成功（有点）让程序注意到错误，并让程序反复询问用户形状和计算体积，直到输入 "quit"。但是，如果用户没有输入 cube 例如，那么最终的输出应该是：
多维数据集体积：您尚未对多维数据集进行任何计算
金字塔体积：6、7
椭圆体积：8
而不是我现在得到的是：
立方体体积：[]
金字塔体积：6、7
椭圆体积：8
有什么方法可以实现正确的最终输出吗？
这是我的代码（它可能不是那么好，但这是我作为初学者和目前所学知识所能做到的最好的）：
#A program that allows the user to continuously pick different shapes and calculate their volumes.
#import all functions from the math module.
import math
#allows the user to input the shape they want to calculate the volume of. Then that input is converted to all upper case
#letters so that no matter what the user enters, it will be recognizable by the program.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
#Initializing the lists for the volumes of the three different shapes as empty lists so that it can be filled
#later on.
VolumeListCube = []
VolumeListPyramid =[]
VolumeListEllipsoid = []
#defining the function that will calculate the volume of the cube and then adding them to the empty list VolumeListCube.
def VolumeCube (sideLength):
volume = sideLength**3
#Adding the values to the list
VolumeListCube.append(volume)
#Sorting the values in the created list in ascending order
VolumeListCube.sort()
return;
#defining the function that will calculate the volume of the pyramid and then adding them to the empty list VolumeListPyramid.
def VolumePyramid (baseLength, height):
volume = round((1/3)*(baseLength**2)*height,1)
#Adding the values to the list
VolumeListPyramid.append(volume)
#Sorting the values in the created list in ascending order
VolumeListPyramid.sort()
return;
#defining the function that will calculate the volume of the ellipsoid and then adding them to the empty list VolumeListEllipsoid.
def VolumeEllipsoid (radius1, radius2, radius3):
volume = round((4/3)*math.pi*radius1*radius2*radius3,1)
#Adding the values to the list
VolumeListEllipsoid.append(volume)
#Sorting the values in the created list in ascending order
VolumeListEllipsoid.sort()
return;
#The first while loop here checks if the user immediately inputs "Quit" or not, if they don't, then the next while loop is
#executed, if they do input "Quit", then the program will print the require message.
while shape != "QUIT":
#This is a infinte while loop since true is always true, this allows the error message at the end to be displayed
#and then loop back to the beginning of this loop, so that it can be executed again.
while True:
if shape in ["CUBE","PYRAMID","ELLIPSOID","QUIT"]:
#These if functions will allow the user to input shape parameters depending on what shape the user has chosen, then
#afterwards, another prompt is show for the user to choose another shape and input that shape's parameters. This will
#continue until the user inputs "Quit", then the required message will be printed and the volume results fot all the
#shapes chosen will be displayed in ascending order.
if shape == "CUBE":
sideLength = int(input("Please enter the length of the sides of the cube:"))
#recalling the function that calculates the volume of the cube.
VolumeCube (sideLength)
#lets the user to input another shape they want to calculate the volume of.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
elif shape == "PYRAMID":
baseLength = int(input("Please enter the base length:"))
height = int(input("Please enter the height:"))
# recalling the function that calculates the volume of the pyramid.
VolumePyramid (baseLength, height)
#lets the user to input another shape they want to calculate the volume of.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
elif shape == "ELLIPSOID":
radius1 = int(input("Please enter the first radius:"))
radius2 = int(input("Please enter the second radius:"))
radius3 = int(input("Please enter the third radius:"))
# recalling the function that calculates the volume of the ellipsoid.
VolumeEllipsoid (radius1, radius2, radius3)
#lets the user to input another shape they want to calculate the volume of.
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
elif shape == "QUIT":
print ("\nYou have come to the end of the session.\nthe volume calculated for each shape are shown below:\n")
print("The volume of the cube(s) is:", VolumeListCube)
print("The volume of the pyramid(s) is:", VolumeListPyramid)
print("The volume of the ellipsoid(s) is:", VolumeListEllipsoid)
#This exits the program to stop repeated prints that would be caused due to the while loop
exit()
else:
print("Error, please enter a valid shape")
shape = input("please enter the shapes you want to calculate the volume of from cube, pyramid and ellipsoid, or Quit: ").upper()
else:
print ("\nYou have come to the end of the session.\nYou have not performed any volume calculations")
TL;DR
没有时间查看您的代码，但我猜您得到的最终结果是 list，因此
cube volumes: []
对此的快速逃避是使用 if 语句来检查列表的大小是否为 0。即，用户没有给出 shape.
所以，一个简单的：
print('cube volumes:',end=' ')
#VolumeListCube is holding the final results
if len(VolumeListCube) == 0:
print("You have not done any calculations for the cube")
else :
#print your values as usual
应该足够了。