Python元素树XML解析：元素对象'；s布尔值很奇怪

我的

xml

文件如下：

<aiml>
<category>
    <pattern>*test*</pattern>
    <template><srai>test</srai></template>
</category>
</aiml>

---

我的python版本是3.6.1。

我检查了类

xml.etree.ElementTree.Element

，他们将来会更改它。谢谢你的提醒

def __bool__(self):
    warnings.warn(
        "The behavior of this method will change in future versions.  "
        "Use specific 'len(elem)' or 'elem is not None' test instead.",
        FutureWarning, stacklevel=2
        )
    return len(self._children) != 0 # emulate old behaviour, for now

---

类可以随意定义True/False。你知道

元素

类是如何定义它的吗？哦，他们将在未来的版本中更改

\uubool\uuu

方法。

def __bool__(self):
    warnings.warn(
        "The behavior of this method will change in future versions.  "
        "Use specific 'len(elem)' or 'elem is not None' test instead.",
        FutureWarning, stacklevel=2
        )
    return len(self._children) != 0 # emulate old behaviour, for now