Python :如何高效地导航XML子节点？
Python :如何高效地导航XML子节点？
提问于 2019-04-18 07:35:40
我正在尝试从XML中提取某些数据点，并尝试了两种方法……
使用ElementTree
- Working和字典使用xmltodict
- 使用XML格式
这是我到目前为止所得到的，
代码
# Packages
# --------------------------------------
import xml.etree.ElementTree as ET
# XML Data
# --------------------------------------
message_xml = \
'<ClinicalDocument> \
<code code="34133-9" displayName="Summarization of Episode Note"/> \
<title>Care Summary</title> \
<recordTarget> \
<patientRole> \
<id assigningAuthorityName="LOCAL" extension="L123456"/> \
<id assigningAuthorityName="SSN" extension="788889999"/> \
<id assigningAuthorityName="GLOBAL" extension="G123456"/> \
<addr use="HP"> \
<streetAddressLine>1000 N SOME AVENUE</streetAddressLine> \
<city>BIG CITY</city> \
<state>NA</state> \
<postalCode>12345-1010</postalCode> \
<country>US</country> \
</addr> \
<telecom nullFlavor="NI"/> \
<patient> \
<name use="L"> \
<given>JANE</given> \
<given>JOE</given> \
<family>DOE</family> \
</name> \
</patient> \
</patientRole> \
</recordTarget> \
</ClinicalDocument>'
# Get Tree & Root
# --------------------------------------
tree = ET.ElementTree(ET.fromstring(message_xml))
root = tree.getroot()
# Iterate
# --------------------------------------
for node in root:
tag = node.tag
attribute = node.attrib
# Get ClinicalDocument.code values
if tag == 'code':
document_code_code = attribute.get('code')
document_code_name = attribute.get('displayName')
else:
pass
# Get ClinicalDocument.recordTarget values
if tag == 'recordTarget':
for child in node.iter():
# Multiple <id> tags
record_target_local = ??
record_target_ssn = ??
record_target_global = ??
# Multiple <given> tags
record_target_name_first = ??
record_target_name_middle = ??
record_target_name_last = ??
else:
pass期望的输出
document_code,document_name,id_local,id_ssn,id_global,name_first, name_middle,name_last
34133-9,Summarization of Episode Note,L123456,788889999,G123456,JANE,JOE,DOE可接受的输出
document_code,document_name,id_type,id,name_first,name_middle,name_last
34133-9,Summarization of Episode Note,LOCAL,L123456,JANE,JOE,DOE
34133-9,Summarization of Episode Note,SSN,788889999,JANE,JOE,DOE
34133-9,Summarization of Episode Note,GLOBAL,G123456,JANE,JOE,DOE问题
如何有效地导航子节点下有多个子节点？
- 如何处理重复的标签(例如：
<id>，<given>)?
回答 1
Stack Overflow用户
回答已采纳
发布于 2019-04-23 03:09:15
如何有效地导航子节点下有多个子节点？
导航XML的一个好方法是使用XPath。ElementTree有limited XPath support，但它似乎足以满足您的需求。如果你最终需要使用更复杂的XPath，我建议你使用XPath in lxml。
如何处理重复的标签(例如：
<id>，<given>)？
这取决于您需要如何处理这些元素。例如，如果您希望每个id元素都有单独的行，则需要遍历每个元素(在ElementTree中使用findall()或在lxml中使用xpath() )。
如果只需要一个值(文本或属性值)，则需要将其范围缩小到XPath中的单个元素。
例如，如果id元素的assigningAuthorityName属性值等于LOCAL，则该元素将为id[@assigningAuthorityName='LOCAL']。
given元素稍微有点棘手；如何区分一个是名字，一个是中间名？我可以看到的唯一方式是位置；第一个given (given[1])是第一个名字，第二个given (given[2])是第二个名字。你能保证总是有两个given元素吗？如果不是这样，您可能需要执行一些检查或try/except语句来获得所需的输出。
另外，由于您要创建csv输出，因此我建议使用csv module；特别是DictWriter。
这将允许您将XML中的值存储在字典中以写入行。您可以为新行创建字典的新副本，同时保持常用值(如document_code和document_name)。
下面的示例将为每个recordTarget创建一个新行。
XML Input (input.xml)
<ClinicalDocument>
<code code="34133-9" displayName="Summarization of Episode Note"/>
<title>Care Summary</title>
<recordTarget>
<patientRole>
<id assigningAuthorityName="LOCAL" extension="L123456"/>
<id assigningAuthorityName="SSN" extension="788889999"/>
<id assigningAuthorityName="GLOBAL" extension="G123456"/>
<addr use="HP">
<streetAddressLine>1000 N SOME AVENUE</streetAddressLine>
<city>BIG CITY</city>
<state>NA</state>
<postalCode>12345-1010</postalCode>
<country>US</country>
</addr>
<telecom nullFlavor="NI"/>
<patient>
<name use="L">
<given>JANE</given>
<given>JOE</given>
<family>DOE</family>
</name>
</patient>
</patientRole>
</recordTarget>
</ClinicalDocument>Python
import csv
import xml.etree.ElementTree as ET
from copy import deepcopy
values_template = {"document_code": "", "document_name": "", "id_local": "", "id_ssn": "",
"id_global": "", "name_first": "", "name_middle": "", "name_last": ""}
with open("output.csv", "w", newline="") as csvfile:
csvwriter = csv.DictWriter(csvfile, delimiter=",", quoting=csv.QUOTE_MINIMAL,
fieldnames=[name for name in values_template])
csvwriter.writeheader()
tree = ET.parse('input.xml')
values_template["document_code"] = tree.find("code").get("code")
values_template["document_name"] = tree.find("code").get("displayName")
for target in tree.findall("recordTarget"):
values = deepcopy(values_template)
values["id_local"] = target.find("patientRole/id[@assigningAuthorityName='LOCAL']").get("extension")
values["id_ssn"] = target.find("patientRole/id[@assigningAuthorityName='SSN']").get("extension")
values["id_global"] = target.find("patientRole/id[@assigningAuthorityName='GLOBAL']").get("extension")
values["name_first"] = target.find("patientRole/patient/name/given[1]").text
values["name_middle"] = target.find("patientRole/patient/name/given[2]").text
values["name_last"] = target.find("patientRole/patient/name/family").text
csvwriter.writerow(values)CSV输出 (output.csv)
document_code,document_name,id_local,id_ssn,id_global,name_first,name_middle,name_last
34133-9,Summarization of Episode Note,L123456,788889999,G123456,JANE,JOE,DOE下面是另一个示例，它将为每个recordTarget/patientRole/id创建一个新行...
Python
import csv
import xml.etree.ElementTree as ET
from copy import deepcopy
values_template = {"document_code": "", "document_name": "", "id": "",
"name_first": "", "name_middle": "", "name_last": ""}
with open("output.csv", "w", newline="") as csvfile:
csvwriter = csv.DictWriter(csvfile, delimiter=",", quoting=csv.QUOTE_MINIMAL,
fieldnames=[name for name in values_template])
csvwriter.writeheader()
tree = ET.parse('input.xml')
values_template["document_code"] = tree.find("code").get("code")
values_template["document_name"] = tree.find("code").get("displayName")
for target in tree.findall("recordTarget"):
values = deepcopy(values_template)
values["name_first"] = target.find("patientRole/patient/name/given[1]").text
values["name_middle"] = target.find("patientRole/patient/name/given[2]").text
values["name_last"] = target.find("patientRole/patient/name/family").text
for role_id in target.findall("patientRole/id"):
values["id"] = role_id.get("extension")
csvwriter.writerow(values)CSV输出 (output.csv)
document_code,document_name,id,name_first,name_middle,name_last
34133-9,Summarization of Episode Note,L123456,JANE,JOE,DOE
34133-9,Summarization of Episode Note,788889999,JANE,JOE,DOE
34133-9,Summarization of Episode Note,G123456,JANE,JOE,DOE页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/55737318
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