Python 3.7：为什么只打印列表中的最后一项？

Question

我正在自学《Python速成班》第2版，遇到一个我无法解决的问题。我重读了本书的前几部分，搜索了互联网并搜索了其他 SO 答案。

官方书的答案用的是字典，我想用的是列表。

程序应该要求输入，将输入添加到列表中并继续重复直到被告知停止。当被告知停止时，应该打印整个列表。

我运行遇到的问题是只有列表中的最后一项在打印。

与其给出答案，不如给我一个提示，让我真正学习。

谢谢，

查德里克

active = True
while active == True:
    places = []
    place = input("\nIf you could visit one place in the world, where would you go? ")
    places.append(place)
    repeat = input("Would you like to let another person respond? (yes/no) ")
    if repeat == 'no':
        print(places)
        active = False

Answer 1

原因是因为您在每次迭代时都将列表重置为空。

尝试以下操作：

active = True
places = []
while active == True:
    place = input("\nIf you could visit one place in the world, where would you go? ")
    places.append(place)
    repeat = input("Would you like to let another person respond? (yes/no) ")
    if repeat == 'no':
        print(places)
        active = False

此外，由于 active 是一个布尔值，您只需要执行 while active:

所以：

active = True
places = []
while active:
    place = input("\nIf you could visit one place in the world, where would you go? ")
    places.append(place)
    repeat = input("Would you like to let another person respond? (yes/no) ")
    if repeat == 'no':
        print(places)
        active = False

Python 3.7：为什么只打印列表中的最后一项？

Python 3.7 : Why is only the last item in a list printing?

list

while-loop

python-3.7