Python 循环控制练习

Question

过去几周我才开始学习 python 超技能。

场景如下：

Write a program that reads from the console integers (one in a line) until their sum is equal to 0. Immediately after that, it should display the sum of the squares of all the entered numbers. It is guaranteed that at some point the sum of the entered numbers will be equal to 0. After that, reading is not necessary to continue.

In case the first integer equals to 0, also stop reading values from the input. Print out 0 instead of the sum of the squares.

For example, we are reading the numbers 1, -3, 5, -6, -10, 13. At this point, we have noticed that the sum of these numbers is 0 and output the sum of their squares, not paying attention to the fact that there are still unread values.

num = int()
listtrigbreak = []
listsquares = []

sumtrig = 0
sumsqua = 0

while sumtrig != 0: # until sum of trig is not 0, 
  num = int(input())     #accept numbers

  if num == "0": # while first input is 0,
    print(0) # print 0
    break    # and break the loop


  listtrigbreak.append(num)   # append num to listtrig
  sumtrig += sum(listtrigbreak) # add sum of list to sumtrig


  for x in listtrigbreak: # for each number in listtrigbreak
    squared = x ** 2     # convert each to squares, save variable
    listsquares.append(squared) # add squared to listsquq
    sumsqua = sum(listsquares)  # sum of squares in listsqua

else:
  print(sumsqua)

我什至无法通过第一个 while 循环。每当我运行它时，它都会跳过整个 while 循环并转到这个：

else:
  print(sumsqua)

我从一开始就很难使用布尔逻辑。我需要解释。

Answer 1

正如其他评论已经指出的那样，while 循环有点棘手，因为您最初将变量声明为 0。您可以使用控制 while 循环的布尔开关，如下所示：

input_integers = []
stop = False

while not stop: # So while we should keep asking user input...
    num = int(input())

    input_integers.append(num)

    if sum(input_integers) == 0 and len(input_integers) > 0:
        print('done')
        stop = True

现在在其中添加其他功能，您就完成了。

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