Question

我如何遍历列表以查找数字是否超过9，如果任何数字超过9，则将该数字减去9。

 public static T FindChild<T>(DependencyObject parent, string childName)
       where T : DependencyObject
    {    
      // Confirm parent and childName are valid. 
      if (parent == null) return null;

      T foundChild = null;

      int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
      for (int i = 0; i < childrenCount; i++)
      {
        var child = VisualTreeHelper.GetChild(parent, i);
        // If the child is not of the request child type child
        T childType = child as T;
        if (childType == null)
        {
          // recursively drill down the tree
          foundChild = FindChild<T>(child, childName);

          // If the child is found, break so we do not overwrite the found child. 
          if (foundChild != null) break;
        }
        else if (!string.IsNullOrEmpty(childName))
        {
          var frameworkElement = child as FrameworkElement;
          // If the child's name is set for search
          if (frameworkElement != null && frameworkElement.Name == childName)
          {
            // if the child's name is of the request name
            foundChild = (T)child;
            break;
          }

 // recursively drill down the tree
          foundChild = FindChild<T>(child, childName);

          // If the child is found, break so we do not overwrite the found child. 
          if (foundChild != null) break;


        else
        {
          // child element found.
          foundChild = (T)child;
          break;
        }
      }

      return foundChild;
    }

Answer 1

你在找这样的东西吗？

一线解决方案：

list = [2,2,12,14,18,9]
print([i-9 if i>9 else i for i in list ])

输出：

[2, 2, 3, 5, 9, 9]

详细解决方案：

以上列表理解与：

相同

new_list=[]
for item in list:
    if item>9:
        new_list.append(item-9)
    else:
        new_list.append(item)

print(new_list)

输出：

[2, 2, 3, 5, 9, 9]

Answer 2

您可以使用列表推导或循环。第一个是更“Pythonic”

list = [2,2,12,14,18,9]
new_list = [x if x <= 9 else x-9 for x in list]

或

list = [2,2,12,14,18,9]
new_list = []
for x in list:
    if x <= 9:
        new_list.append(x)
    else:
        new_list.append(x-9)

Answer 3

我认为你需要像模数这样的东西。

list = [2, 2, 12, 14, 18, 9]
new_list = [9 if x%9==0 else x%9 for x in list]
print(new_list)

输出：

[2, 2, 3, 5, 9, 9]

如果您想减去9次，请使用：

new_list = [x-9 if x>9 else x for x in list]

列表和循环以及更改元素

3 个答案: