使用Python的xml.dom.minidom

Question

我試圖使用Python的xml.dom.minidom，和我得到了以下錯誤：

>>> from xml.dom import minidom 
>>> xdocument = minidom.Document() 
>>> xrss = minidom.Element("rss") 
>>> xdocument.appendChild(xrss) 
<DOM Element: rss at 0xc1d0f8> 
>>> xchannel = minidom.Element("channel") 
>>> xrss.appendChild(xchannel) 
Traceback (most recent call last): 
    File "C:\Program Files\Wing IDE 3.2\src\debug\tserver\_sandbox.py", line 1, in ? 
    # Used internally for debug sandbox under external interpreter 
    File "c:\Python24\Lib\xml\dom\minidom.py", line 123, in appendChild 
    _clear_id_cache(self) 
    File "c:\Python24\Lib\xml\dom\minidom.py", line 1468, in _clear_id_cache 
    node.ownerDocument._id_cache.clear() 
AttributeError: 'NoneType' object has no attribute '_id_cache' 
>>> 

任何人有任何想法，爲什麼？

Answer 1

使用xdocument.createElement('name')創建新元素。這是在DOM中執行此操作的標準方法。

Answer 2

將xdocument.appendChild(xrss)替換爲xrss = xdocument.appendChild(xrss)。從docs：

Node.appendChild(newChild) Add a new child node to this node at the end of the list of children, returning newChild. If the node was already in in the tree, it is removed first.

所以，你需要從appendChild分配xrss返回的元素。