Python使用xml.dom.minidom解析XML-提取列表中的项目

Question

I have lengthy xml this actually ebay listings using ebay api, I am trying to extract following structure in that xml dom:

I am only putting the segment that I am having trouble with, please let me know if you need to see the entire file, I could upload it to a location or do an attachment as a picture.

<ItemSpecifics>
<NameValueList>
<Name>Room</Name>
<Value>Living Room</Value>
</NameValueList>
<NameValueList>
<Name>Type</Name>
<Value>Sofa Set</Value>
</NameValueList>
<NameValueList>...</NameValueList>
<NameValueList>
<Name>Upholstery Fabric</Name>
<Value>Microfiber</Value>
</NameValueList>
<NameValueList>
<Name>Color</Name>
<Value>Beiges</Value>
</NameValueList>
<NameValueList>
<Name>Style</Name>
<Value>Contemporary</Value>
</NameValueList>
<NameValueList>
<Name>MPN</Name>
<Value>F7615, F7616, F7617, F7618, F7619, F7620</Value>
</NameValueList>
</ItemSpecifics>

Here is dom structure for another ebay item:

ItemSpecifics>
<NameValueList>
<Name>Brand</Name>
<Value>Nikon</Value>
</NameValueList>
<NameValueList>
<Name>Model</Name>
<Value>D3100</Value>
</NameValueList>
<NameValueList>
<Name>MPN</Name>
<Value>9798</Value>
</NameValueList>
<NameValueList>
<Name>Type</Name>
<Value>Digital SLR</Value>
</NameValueList>
<NameValueList>
<Name>Megapixels</Name>
<Value>14.2 MP</Value>
</NameValueList>
<NameValueList>
<Name>Optical Zoom</Name>
<Value>3.1x</Value>
</NameValueList>
<NameValueList>
<Name>Screen Size</Name>
<Value>3"</Value>
</NameValueList>
<NameValueList>
<Name>Color</Name>
<Value>Black</Value>
</NameValueList>
</ItemSpecifics>

But when I tried to extract above elements I endup getting following error:

   attID=att.attributes.getNamedItem('Name').nodeValue
AttributeError: 'NoneType' object has no attribute 'nodeValue'

this is what I get right after I parse response:

[<DOM Element: NameValueList at 0x103398878>, <DOM Element: NameValueList at 0x103398ab8>, <DOM Element: NameValueList at 0x103398cf8>, <DOM Element: NameValueList at 0x103398f38>, <DOM Element: NameValueList at 0x1033b31b8>, <DOM Element: NameValueList at 0x1033b33f8>, <DOM Element: NameValueList at 0x1033b3638>, <DOM Element: NameValueList at 0x1033b3878>]

And this is what I get inside my for loop before getting the error:

<DOM Element: NameValueList at 0x103398878>

Here is my code:

  results = {}
  attributeSet=response.getElementsByTagName('NameValueList')
  print attributeSet
  attributes={}
  for att in attributeSet:
    print att
    attID=att.attributes.getNamedItem('Name').nodeValue
    attValue=getSingleValue(att,'Value')
    attributes[attID]=attValue
  result['attributes']=attributes
  return result

This is my xml request method:

def sendRequest(apicall,xmlparameters):
  connection = httplib.HTTPSConnection(serverUrl)
  connection.request("POST", '/ws/api.dll', xmlparameters, getHeaders(apicall))
  response = connection.getresponse()
  if response.status != 200:
    print "Error sending request:" + response.reason
  else: 
    data = response.read()
    connection.close()
  return data

Answer 1

attributes.getNamedItem() gives you the attributes of an element, not it's children, and a <NameValueList> element has no Name attribute, only <Name> elements. You'd have to loop over the contained elements of <NameValueList> , or use .getElementsByTagName('Name') and .getElementsByTagName('Value') to get individual sub-nodes.

Do yourself a big favour though and use the ElementTree API instead; that API is far pythononic and easier to use than the XML DOM API:

from xml.etree import ElementTree as ET

etree = ET.fromstring(data)
results = {}
for nvl in etree.findall('NameValueList'):
    name = nvl.find('Name').text
    value = nvl.find('Value').text
    results[name] = value