将字符串转换为字典后，“列表索引必须是整数，而不是str”

Question

使用POST请求，我收到了此回复

<?xml version="1.0" encoding="UTF-8"?>
<response version="1.1">
   <accommodations>
      <accommodation name="accom1">
         <concepts>
            <concept name="concept1-1">
               <boards>
                  <board name="board1-1">
                     <description>description</description>
                  </board>
                  <board name="board1-2">
                     <description>description</description>
                  </board>
        </concept>
            <concept name="concept2-1">
               <boards>
                  <board name="board2-1">
                     <description>description</description>
                  </board>
                  <board name="board2-2">
                     <description>description</description>
                  </board>
        </boards>
        </concept>
     </concepts>
      </accommodation>
      <accommodation name="accom2">
         <concepts>
            <concept name="concept3-1">
               <boards>
                  <board name="board3-1">
                     <description>description</description>
                  </board>
                  <board name="board3-2">
                     <description>description</description>
                  </board>
        </concept>
            <concept name="concept4-1">
               <boards>
                  <board name="board4-1">
                     <description>description</description>
                  </board>
                  <board name="board4-2">
                     <description>description</description>
                  </board>
        </boards>
        </concept>
     </concepts>
       </accommodation>
    </accommodations>
</response>

以下是请求代码：

my_request = urllib2.Request(url, message)
response_xml = urllib2.urlopen(my_request)
my_response = response_xml.read()

然后我将字符串转换为字典：

def etree_to_dict(t):
        d = {t.tag: {} if t.attrib else None}
        children = list(t)
        if children:
                dd = defaultdict(list)
                for dc in map(etree_to_dict, children):
                        for k, v in dc.iteritems():
                                dd[k].append(v)
                d = {t.tag: {k:v[0] if len(v) == 1 else v for k, v in dd.iteritems()}}
        if t.attrib:
                d[t.tag].update(('@' + k, v) for k, v in t.attrib.iteritems())
        if t.text:
                text = t.text.strip()
                if children or t.attrib:
                        if text:
                                d[t.tag]['#text'] = text
                else:
                        d[t.tag] = text
        return d    
my_result = ET.fromstring(my_response.decode('ascii', 'ignore'))
d = globalvars.etree_to_dict(my_result)

然后我尝试将一些数据从字典保存到数据库。当我尝试保存name="accom1"时，everythig可以正常工作：

 my_data=d['response']['accommodations']['accommodation']
        for n in my_data.get('accommodation'):
                p = XMLData(
                        name = n.get('@name')
                )

但是当我尝试保存board name时，出现了一个错误： list indices must be integers, not str

 my_data=d['response']['accommodations']['accommodation']['concepts']
    for n in my_data:
            p = XMLData(
                    board = n['@name']
            )

我不知道为什么会这样。你能帮我吗？非常感谢。