xml.dom.minidom python问题

Question

from xml.dom.minidom import *

resp = "<title> This is a test! </title>"

rssDoc = parseString(resp)

titles = rssDoc.getElementsByTagName('title')

moo = ""

for t in titles:
    moo += t.nodeValue;

给出以下错误：

main.py, line 42, in
       get moo += t.nodeValue;
TypeError: cannot concatenate 'str' and 'NoneType' objects

Answer 1

<title>节点包含一个文本节点作为子节点。也许你想迭代子节点？像这样：

from xml.dom.minidom import *

resp = "<title> This is a test! </title>"

rssDoc = parseString(resp)

titles = rssDoc.getElementsByTagName('title')

moo = ""

for t in titles:
    for child in t.childNodes:
        if child.nodeType == child.TEXT_NODE:
            moo += child.data
        else:
            moo += "not text "

print moo

要学习xml.dom.minidom，您还可以查看section in Dive Into Python。

Answer 2

因为它不是文本节点，而是元素节点。包含“This is a test！”字符串的文本节点实际上是此元素节点的子节点。

所以你可以尝试这个（未经测试，不假设存在文本节点）：

if t.nodeType == t.ELEMENT_NODE:
    moo += t.childNodes[0].data

Answer 3

因为t.nodeType当然不等于t.TEXT_NODE。