如何在 python 中'int'对象不可迭代的情况下解决此错误

Question

  def activityNotifications(expenditure, d):
      notif = 0
      if(d%2):
          x = math.floor(d/2)
          y = math.ceil(d/2)
          for i in range(d,len(expenditure)):
               if(sum(expenditure[i-x],expenditure[i-y])/2 <= expenditure[i]):
               notif+=1
      else:
          for i in range(d,len(expenditure)-1):
               if(expenditure[i - d/2] <= expenditure[i]):
               notif+=1
  return notif

activityNotifications中的文件"Solution.py"，第16行如果(sum(支出[i-x]，支出[i-y](/2<=支出[i](：TypeError:"int"对象不是可迭代的

Answer 1

您应该更改此行if(sum(expenditure[i-x],expenditure[i-y])/2 <= expenditure[i]):

应该是：

if(expenditure[i-x]+expenditure[i-y])/2 <= expenditure[i]:

sum函数的语法：

sum(可迭代，开始(

• iterable：iterable可以是任何列表、元组或字典，但最重要的是，它应该由数字组成
• start：此start添加到迭代中的数字

Answer 2

sum(expenditure[i-x],expenditure[i-y])不会做你认为它会做的事情。

第一个参数必须是可迭代的，第二个(可选(参数是起始值(默认为0(。将2个整数传递给sum毫无意义。

如果真的想使用sum，你必须写：

sum(expenditure[i-a] for a in [x,y])

为什么让事情变得复杂(表现不佳(？do:

if expenditure[i-x] + expenditure[i-y] <= expenditure[i]: