在Python中为旧Macdonald使用列表和循环

Question

我正在做学校作业，遇到了一些麻烦。为此，我需要使用列表和循环让用户能够将动物和声音输入到两个列表中。然后循环应该以一组的形式输出歌词，在适当的时候使用动物和声音，比如：

And on this farm he had a dog...etc and going through the song, and the next going And on this far he had a cat...etc through all animals and sounds in the list

现在它部分起作用。用户可以输入三种动物和三种声音，然后打印将运行，但只输出列表中的最后一项。我希望它打印的歌词与列表中的所有条目。我还希望用户能够用-1取消，但我尝试过的一切都没有起作用。如果有人能帮忙，那就太好了！到目前为止，我已将代码包括在下面：

for song in range (3):
    animal = input("Please Input an Animal: ")
    sound = input("Please Input a Sound: ")
    
    lyrics = "Old Macdonald had a farm, E- I- E- I- O," "And on that farm he had a %s, E- I- E- I- O." "With a %s - %s here,And a %s - %s there," "Here a %s, there a %s, Everywhere a %s - %s" "Old Macdonald had a farm, E- I- E- I- O!" % (animal, sound, sound, sound, sound, sound, sound, sound, sound)
print(lyrics)

Answer 1

试试这个

# if length != length2: (code to check the lists are of the same length)

animal_list = ['Dog', 'Cat', 'Horse', 'Goat'] # using this in place of appending user input to an empty list
sound_list = ['Bark', 'Meow', 'Neigh', 'Bleat']
length = len(animal_list) 
# length2 = len(sound_list)    

for x in range(length):
sentence = 'start here ' + animal_list[x] + ' body of song ' + sound_list[x] + ' rest of song'
print(sentence)

Answer 2

Sunero4已经解释了为什么动物和声音变量只分配给最后一个用户条目。 我在他的答案中添加了一些格式，并在每个用户输入后添加sys.exit（0），以检查是否输入了-1，以便我们可以退出。请注意，我们使用“导入系统”来调用此模块。我不知道你是否已经在课堂上讲过了。如果不是，我建议您看看当前的课程笔记如何处理这个问题

import sys

lyrics_list = []

for song in range (3):
    animal = input("Please Input an Animal: ")
    if animal == '-1':
        sys.exit(0)
    sound = input("Please Input a Sound: ")
    if sound == '-1':
        sys.exit(0)     
    
    lyrics = "Old Macdonald had a farm, E- I- E- I- O," " And on that farm he had a %s, E- I- E- I- O." " With a %s - %s here, and a %s - %s there," " here a %s, there a %s, everywhere a %s - %s" " Old Macdonald had a farm, E- I- E- I- O!" % (animal, sound, sound, sound, sound, sound, sound, sound, sound)
    lyrics_list.append(lyrics)

for lyric in lyrics_list:
    print(lyric)

编辑：您可以用quit（）替换sys.exit（0），它也会这样做。有关sys.exit（）和quit（）之间差异的更多详细信息，请查看此处Python exit commands - why so many and when should each be used?

Answer 3

因此，这并没有像您预期的那样起作用，因为您只是重新分配动物和声音变量，而不是将它们添加到列表中。要使其工作，以便用户可以输入三种声音和动物，您可以执行以下操作：

    lyrics_list = []

    for song in range (3):
        animal = input("Please Input an Animal: ")
        sound = input("Please Input a Sound: ")
         
    
        lyrics = "Old Macdonald had a farm, E- I- E- I- O," "And on that farm he had a %s, E- I- E- I- O." "With a %s - %s here,And a %s - %s there," "Here a %s, there a %s, Everywhere a %s - %s" "Old Macdonald had a farm, E- I- E- I- O!" % (animal, sound, sound, sound, sound, sound, sound, sound, sound)
        lyrics_list.append(lyrics)

    for lyric in lyrics_list:
        print(lyric)