使用xml.dom.minidom更新元素值

2024-03-28 14:57:16 发布

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我有一个XML结构,它看起来类似于:

<Store>
   <foo>
      <book>
        <isbn>123456</isbn>
      </book>
      <title>XYZ</title>
      <checkout>no</checkout>
   </foo>

   <bar>
      <book>
        <isbn>7890</isbn>
      </book>
      <title>XYZ2</title>
      <checkout>yes</checkout>
   </bar>
</Store>

仅使用xml.dom.minidom(限制)我想

1)遍历XML文件

2)根据父元素搜索/获取特定元素

示例:author1的checkout元素,author2的isbn

3)更改/设置该元素的值

4)将新的XML结构写入文件

有人能帮忙吗?

谢谢你!

更新

这就是我到现在为止所做的

import xml.dom.minidom
checkout = "yes"

def getLoneChild(node, tagname):

  assert ((node is not None) and (tagname is not None))
  elem = node.getElementsByTagName(tagname)
  if ((elem is None) or (len(elem) != 1)):
    return None
  return elem

def getLoneLeaf(node, tagname):

  assert ((node is not None) and (tagname is not None))
  elem = node.getElementsByTagName(tagname)
  if ((elem is None) or (len(elem) != 1)):
    return None
  leaf = elem[0].firstChild
  if (leaf is None):
    return None
  return leaf.data


def setcheckout(node, tagname):

  assert ((node is not None) and (tagname is not None))
  child = getLoneChild(node, 'foo')
  Check = getLoneLeaf(child[0],'checkout')
  Check = tagname
  return Check

doc = xml.dom.minidom.parse('test.xml') 
root = doc.getElementsByTagName('Store')[0]
output = setcheckout(root, checkout)

tmp_config = '/tmp/tmp_config.xml' 
fw = open(tmp_config, 'w')
fw.write(doc.toxml())
fw.close()

Tags: nonenode元素returntitleisnotxml
1条回答
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1楼 · 发布于 2024-03-28 14:57:16

我不太清楚你说的“结帐”是什么意思。此脚本将找到元素并更改该元素的值。也许你可以根据自己的具体需要来调整它。

import xml.dom.minidom as DOM

# find the author as a child of the "Store"
def getAuthor(parent, author):
  # by looking at the children
  for child in [child for child  in parent.childNodes 
                if child.nodeType != DOM.Element.TEXT_NODE]:
    if child.tagName == author:
      return child
  return None

def alterElement(parent, attribute, newValue):
  found = False;
  # look through the child elements, skipping Text_Nodes 
  #(in your example these hold the "values"
  for child in [child for child  in parent.childNodes 
                if child.nodeType != DOM.Element.TEXT_NODE]:

    # if the child element tagName matches target element name
    if child.tagName == attribute:
      # alter the data, i.e. the Text_Node value, 
      # which is the firstChild of the "isbn" element
      child.firstChild.data = newValue
      return True

    else:
      # otherwise look at all the children of this node.
      found = alterElement(child, attribute, newValue)

    if found:
      break 

  # return found status
  return found

doc = DOM.parse("test.xml")
# This assumes that there is only one "Store" in the file
root = doc.getElementsByTagName("Store")[0]

# find the author
# this assumes that there are no duplicate author names in the file
author = getAuthor(root, "foo")
if not author:
  print "Author not found!"
else:
  # alter an element
  if not alterElement(author, "isbn", "987654321"):
    print "isbn not found"
  else:
    # output the xml
    tmp_config = '/tmp/tmp_config.xml'
    f = open(tmp_config, 'w')
    doc.writexml( f )
    f.close()

一般的想法是,将作者的名字与“Store”元素的子标记名相匹配,然后通过作者的子标记名递归,寻找与目标元素标记名的匹配。在这个解决方案中有很多假设,但它可能会让你开始。尝试在不使用递归的情况下处理XML这样的层次结构是很痛苦的。

干杯, 菲尔


回想起来,“alterElement”函数中有一个错误。我已经修复了这个(注意“found”变量)

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