Moreover, an element that has no content is represented by an empty child list, but a self-closed tag is represented by None. Listing 2 shows this structure in action.

而一个没有内容的元素由一个空的子列表表示，但是一个自封闭的标记由None表示。

youdao

Moreover, an element that has no content is represented by an empty child list, but a self-closed tag is represented by None. Listing 2 shows this structure in action.

而一个没有内容的元素由一个空的子列表表示，但是一个自封闭的标记由None表示。

youdao