如何在python中从URL读取XML文件？

Question

我想访问子节点中存在的信息。这是因为文件的结构吗？

尝试分别在文件中提取作者子节点信息并运行python代码。这很好

import urllib
import xml.etree.ElementTree as ET

url = 'https://dailymed.nlm.nih.gov/dailymed/services/v2/spls/fe9e8b7d-61ea-409d-84aa-3ebd79a046b5.xml'

print 'Retrieving', url

document = urllib.urlopen (url).read()
print 'Retrieved', len(document), 'characters.'

print document[:50]

tree = ET.fromstring(document)

lst = tree.findall('title')
print lst[:100]

Answer 1

由于命名空间，您找不到标题元素。

下面是一个示例代码：

• 来自“文档”标签的标题
• 内部“组件”标签的标题

    import xml.etree.ElementTree as ET
    import urllib.request

    url = 'https://dailymed.nlm.nih.gov/dailymed/services/v2/spls/fe9e8b7d-61ea-409d-84aa-3ebd79a046b5.xml'
    response = urllib.request.urlopen(url).read()
    tree = ET.fromstring(response)


    for docTitle in tree.findall('{urn:hl7-org:v3}title'):
        print(docTitle.text)

    for compTitle in tree.findall('.//{urn:hl7-org:v3}title'):
        print(compTitle.text)

UPDATE

如果需要搜索XML节点，则应使用xPath Expressions

例：

NS = '{urn:hl7-org:v3}'
ID = '829076996'    # ID TO BE FOUND

# XPATH TO FIND AUTHORS BY ID (search ID and return related author node)
xPathAuthorById = ''.join([
    ".//",
    NS, "author/",
    NS, "assignedEntity/",
    NS, "representedOrganization/",
    NS, "id[@extension='", ID,
    "']/../../.."
    ])

# XPATH TO FIND AUTHOR NAME ELEMENT
xPathAuthorName = ''.join([
    "./",
    NS, "assignedEntity/",
    NS, "representedOrganization/",
    NS, "name"
    ])

# FOR EACH AUTHOR FOUND, SEARCH ATTRIBUTES (example name)
for author in tree.findall(xPathAuthorById):
    name = author.find(xPathAuthorName)
    print(name.text)

此示例打印ID 829076996的作者姓名

更新2

您可以使用findall方法轻松处理所有assignedEntity标记。对于它们中的每一个，您可以拥有多个产品，因此需要另一种findall方法（参见下面的示例）。

xPathAssignedEntities = ''.join([
    ".//",
    NS, "author/",
    NS, "assignedEntity/",
    NS, "representedOrganization/",
    NS, "assignedEntity/", 
    NS, "assignedOrganization/", 
    NS, "assignedEntity"
    ])

xPathProdCode = ''.join([
    NS, "actDefinition/",
    NS, "product/",
    NS, "manufacturedProduct/",
    NS, "manufacturedMaterialKind/",
    NS, "code"
    ])


# GET ALL assignedEntity TAGS
for assignedEntity in tree.findall(xPathAssignedEntities):

    # GET ID AND NAME OF assignedEntity
    id = assignedEntity.find(NS + 'assignedOrganization/'+ NS + 'id').get('extension')
    name = assignedEntity.find(NS + 'assignedOrganization/' + NS + 'name').text

    # FOR EACH assignedEntity WE CAN HAVE MULTIPLE <performance> TAGS
    for performance in assignedEntity.findall(NS + 'performance'):
        actCode = performance.find(NS + 'actDefinition/'+ NS + 'code').get('displayName')
        prodCode = performance.find(xPathProdCode).get('code')
        print(id, '\t', name, '\t', actCode, '\t', prodCode)

这是结果：

829084545    Pfizer Pharmaceuticals LLC      ANALYSIS    0049-0050 
829084545    Pfizer Pharmaceuticals LLC      ANALYSIS    0049-4900 
829084545    Pfizer Pharmaceuticals LLC      ANALYSIS    0049-4910 
829084545    Pfizer Pharmaceuticals LLC      ANALYSIS    0049-4940 
829084545    Pfizer Pharmaceuticals LLC      ANALYSIS    0049-4960 
829084545    Pfizer Pharmaceuticals LLC      API MANUFACTURE     0049-0050
829084545    Pfizer Pharmaceuticals LLC      API MANUFACTURE     0049-4900
829084545    Pfizer Pharmaceuticals LLC      API MANUFACTURE     0049-4910
829084545    Pfizer Pharmaceuticals LLC      API MANUFACTURE     0049-4940
829084545    Pfizer Pharmaceuticals LLC      API MANUFACTURE     0049-4960
829084545    Pfizer Pharmaceuticals LLC      MANUFACTURE     0049-4900 
829084545    Pfizer Pharmaceuticals LLC      MANUFACTURE     0049-4910 
829084545    Pfizer Pharmaceuticals LLC      MANUFACTURE     0049-4960 
829084545    Pfizer Pharmaceuticals LLC      PACK    0049-4900 
829084545    Pfizer Pharmaceuticals LLC      PACK    0049-4910 
829084545    Pfizer Pharmaceuticals LLC      PACK    0049-4960 
618054084    Pharmacia and Upjohn Company LLC    ANALYSIS    0049-0050
618054084    Pharmacia and Upjohn Company LLC    ANALYSIS    0049-4940
829084552    Pfizer Pharmaceuticals LLC      PACK    0049-4900 
829084552    Pfizer Pharmaceuticals LLC      PACK    0049-4910 
829084552    Pfizer Pharmaceuticals LLC      PACK    0049-4960

Answer 2

您可以使用xmltodict从请求的XML数据生成python字典。

这是一个基本的例子：

import urllib2
import xmltodict

def foobar(request):
    file = urllib2.urlopen('https://dailymed.nlm.nih.gov/dailymed/services/v2/spls/fe9e8b7d-61ea-409d-84aa-3ebd79a046b5.xml')
    data = file.read()
    file.close()

    data = xmltodict.parse(data)
    return {'xmldata': data}

Answer 3

我通常更喜欢beautifulsoup with lxml解析器来解析xml。示例代码如下

import requests
from bs4 import BeautifulSoup

url = 'https://dailymed.nlm.nih.gov/dailymed/services/v2/spls/fe9e8b7d-61ea-409d-84aa-3ebd79a046b5.xml'

document = requests.get(url)

soup= BeautifulSoup(document.content,"lxml-xml")
print (soup.find("title"))

产量

<title>These highlights do not include all the information needed to use ZOLOFT safely and effectively. See full prescribing information for ZOLOFT. <br/>
<br/>ZOLOFT (sertraline hydrochloride) tablets, for oral use <br/>ZOLOFT (sertraline hydrochloride) oral solution <br/>Initial U.S. Approval: 1991</title>

然后，您可以使用像find和find_all这样的beautifulsoup提供的方法来查找相应的节点或子节点