在 Python 中为 Old Macdonald 使用列表和循环

Question

我正在完成一项学校作业，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。然后应该循环输出一组歌词，在适当的地方一次使用动物和声音，所以像：

在这个农场里，他养了一只狗……等等，正在播放这首歌，然后是下一首歌曲。在这么远的地方，他有一只猫……等等，通过列表中的所有动物和声音

现在它部分工作。用户可以输入三种动物和三种声音，然后打印将运行，但它只会输出列表中的最后一个条目。我希望它打印包含列表中所有条目的歌词。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。如果有人可以提供帮助，那就太好了！到目前为止，我已经在下面包含了我的代码：

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

Sunero4 已经解释了为什么只在最后一个用户条目中分配了动物和声音变量。 我在他的答案中添加了一些格式，并在每次用户输入后添加到 sys.exit(0) 中，以检查是否输入了 -1 以便我们可以退出。请注意，我们使用“import sys”来调用此模块。我不知道你是否已经在课堂上讲过了。如果没有，我建议你看看你当前的课程笔记是如何处理这个问题的。

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

Answer 2

所以这没有按预期工作的原因是因为您只是重新分配了动物和声音变量，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)

Answer 3

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)