如何在python中使用xpath提取xml中的特定节点

我正在使用AmazonAPI进行项目查找

它返回这种类型的

xml

对象。我想知道如何使用

xpath

提取

的

超链接

但这张单子是空的

编辑：

当我执行
[result.xpath（'/*'）中x的x.tag]
时，我得到了这个结果：

['{http://webservices.amazon.com/AWSECommerceService/2011-08-01}ItemLookupResponse'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}操作请求'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}HTTPHeaders'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}标题“，”{http://webservices.amazon.com/AWSECommerceService/2011-08-01}请求ID'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}参数'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}论点'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}请求处理时间'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}项目'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}请求'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}是有效的'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}ItemLookupRequest'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}IdType'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}ItemId'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}响应组'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}变量页'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}包括查看摘要'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}截断视图卫星'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}项目'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}阿辛'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}CustomerReviews'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}IFrameURL'，'{http://webservices.amazon.com/AWSECommerceService/2011-08-01}HasReviews']

编辑2：
我现在以
http://www.amazon.com/reviews/iframe?akid=HIDDEN&alinkCode=xm2&asin=B00062B6QY&atag=HIDDEN&exp=2014-01-28T07%3A55%3A45Z&summary=0&truncate=256&v=2&sig=HIDDED%3D
忽略命名空间时进行查询

>>> result.xpath('//*[local-name()="IFrameURL"]/text()')[0].strip()
'http://www.amazon.com/reviews/iframe?akid=[AWS Access Key ID]&asin=0316067938&exp=2011-08-01T17%3A54%3A07Z&linkCode=xm2&summary=0&tag=ws&truncate=256&v=2&sig=[Signature]'

我得到
索引器：列表索引超出范围
结果。xpath（'//iframeurl/text（）'）
正在返回空列表
[x.tag for x in result.xpath（'//*'）]
若要查看其中的内容，我已将我在上面的编辑中得到的内容包括在内。我确实看到了
iframeurl
谢谢。这很有帮助，但你能解释一下你在上面做了什么吗？我已经粘贴了我得到的文本。现在我必须解析它以获得评论。
result = api.item_lookup('0316067938', ResponseGroup='Reviews',
     TruncateReviewsAt=256, IncludeReviewsSummary=False)
print result.xpath('//IFrameURL')

>>> result.xpath('//*[local-name()="IFrameURL"]/text()')[0].strip()
'http://www.amazon.com/reviews/iframe?akid=[AWS Access Key ID]&asin=0316067938&exp=2011-08-01T17%3A54%3A07Z&linkCode=xm2&summary=0&tag=ws&truncate=256&v=2&sig=[Signature]'