Python解析XML文件并将每个节点另存为文件

因此，我想解析一个包含许多节点（和多个名称空间）的XML文件。 目标是提取名为CodeList的每个节点，并将每个节点保存在一个新的xml文件下，该文件名为每个节点的OID属性

下面是原始XML的提取：

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="../xsl/controlledterminology1-0-0.xsl"?>
<ODM xmlns="http://www.cdisc.org/ns/odm/v1.3"
  xmlns:xs="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:nciodm="http://ncicb.nci.nih.gov/xml/odm/EVS/CDISC"
  xs:schemaLocation="http://www.nci.nih.gov/EVS/CDISC ../schema/controlledterminology1-0-0.xsd"
  FileType="Snapshot"
  FileOID="CDISC_CT.SDTM.2011-06-10"
  Granularity="Metadata"
  CreationDateTime="2011-06-07T07:35:51"
  AsOfDateTime="2011-06-10T00:00:00"
  ODMVersion="1.3.1"
  Originator="CDISC XML Technologies Team (SAS 9.02.02M3P04132010)"
  SourceSystem="NCI Thesaurus"
  SourceSystemVersion="2011-06-10">
  <Study OID="CDISC_CT.SDTM.2011-06-10">
    <GlobalVariables>
      <StudyName>CDISC SDTM ControlledTerminology</StudyName>
      <StudyDescription>CDISC SDTM Controlled Terminology, 2011-06-10</StudyDescription>
      <ProtocolName>CDISC SDTM Controlled Terminology</ProtocolName>
    </GlobalVariables>
    <MetaDataVersion OID="CDISC_CT_MetaDataVersion.SDTM.2011-06-10"
      Name="CDISC SDTM Controlled Terminology"
      Description="CDISC SDTM Controlled Terminology, 2011-06-10">
      <CodeList OID="CL.C66767.ACN" Name="Action Taken with Study Treatment" DataType="text" nciodm:ExtCodeID="C66767" nciodm:CodeListExtensible="No">
        <Description>
          <TranslatedText xml:lang="en">Action Taken with Study Treatment</TranslatedText>
        </Description>
        <EnumeratedItem CodedValue="DOSE INCREASED" nciodm:ExtCodeID="C49503">
          <nciodm:CDISCDefinition>An indication that a medication schedule was modified by addition; either by changing the frequency, strength or amount. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Dose Increased</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="DOSE NOT CHANGED" nciodm:ExtCodeID="C49504">
          <nciodm:CDISCDefinition>An indication that a medication schedule was maintained. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Dose Not Changed</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="DOSE REDUCED" nciodm:ExtCodeID="C49505">
          <nciodm:CDISCDefinition>An indication that a medication schedule was modified by subtraction, either by changing the frequency, strength or amount. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Dose Reduced</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="DRUG INTERRUPTED" nciodm:ExtCodeID="C49501">
          <nciodm:CDISCDefinition>An indication that a medication schedule was modified by temporarily terminating a prescribed regimen of medication. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Drug Interrupted</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="DRUG WITHDRAWN" nciodm:ExtCodeID="C49502">
          <nciodm:CDISCDefinition>An indication that a medication schedule was modified through termination of a prescribed regimen of medication. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Drug Withdrawn</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="NOT APPLICABLE" nciodm:ExtCodeID="C48660">
          <nciodm:CDISCSynonym>NA</nciodm:CDISCSynonym>
          <nciodm:CDISCDefinition>Determination of a value is not relevant in the current context. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Not Applicable</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="UNKNOWN" nciodm:ExtCodeID="C17998">
          <nciodm:CDISCSynonym>U</nciodm:CDISCSynonym>
          <nciodm:CDISCSynonym>Unknown</nciodm:CDISCSynonym>
          <nciodm:CDISCDefinition>Not known, not observed, not recorded, or refused. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Unknown</nciodm:PreferredTerm>
        </EnumeratedItem>
        <nciodm:CDISCSubmissionValue>ACN</nciodm:CDISCSubmissionValue>
        <nciodm:CDISCSynonym>Action Taken with Study Treatment</nciodm:CDISCSynonym>
        <nciodm:PreferredTerm>CDISC SDTM Action Taken with Study Treatment Terminology</nciodm:PreferredTerm>
      </CodeList>
      <CodeList OID="CL.C66768.OUT" Name="Outcome of Event" DataType="text" nciodm:ExtCodeID="C66768" nciodm:CodeListExtensible="No">
        <Description>
          <TranslatedText xml:lang="en">A condition or event that is attributed to the adverse event and is the result or conclusion of the adverse event. (NCI)</TranslatedText>
        </Description>
        <EnumeratedItem CodedValue="FATAL" nciodm:ExtCodeID="C48275">
          <nciodm:CDISCSynonym>Grade 5</nciodm:CDISCSynonym>
          <nciodm:CDISCSynonym>5</nciodm:CDISCSynonym>
          <nciodm:CDISCDefinition>The termination of life as a result of an adverse event. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Death Related to Adverse Event</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="NOT RECOVERED/NOT RESOLVED" nciodm:ExtCodeID="C49494">
          <nciodm:CDISCDefinition>One of the possible results of an adverse event outcome that indicates that the event has not improved or recuperated. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Not Recovered or Not Resolved</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="RECOVERED/RESOLVED" nciodm:ExtCodeID="C49498">
          <nciodm:CDISCDefinition>One of the possible results of an adverse event outcome that indicates that the event has improved or recuperated. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Recovered or Resolved</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="RECOVERED/RESOLVED WITH SEQUELAE" nciodm:ExtCodeID="C49495">
          <nciodm:CDISCDefinition>One of the possible results of an adverse event outcome where the subject recuperated but retained pathological conditions resulting from the prior disease or injury. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Recovered or Resolved with Sequelae</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="RECOVERING/RESOLVING" nciodm:ExtCodeID="C49496">
          <nciodm:CDISCDefinition>One of the possible results of an adverse event outcome that indicates that the event is improving. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Recovering or Resolving</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="UNKNOWN" nciodm:ExtCodeID="C17998">
          <nciodm:CDISCSynonym>U</nciodm:CDISCSynonym>
          <nciodm:CDISCSynonym>Unknown</nciodm:CDISCSynonym>
          <nciodm:CDISCDefinition>Not known, not observed, not recorded, or refused. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Unknown</nciodm:PreferredTerm>
        </EnumeratedItem>
        <nciodm:CDISCSubmissionValue>OUT</nciodm:CDISCSubmissionValue>
        <nciodm:CDISCSynonym>Outcome of Event</nciodm:CDISCSynonym>
        <nciodm:PreferredTerm>CDISC SDTM Adverse Event Outcome Terminology</nciodm:PreferredTerm>
      </CodeList>
      <CodeList OID="CL.C66780.AGESPAN" Name="Age Span" DataType="text" nciodm:ExtCodeID="C66780" nciodm:CodeListExtensible="Yes">
        <Description>
          <TranslatedText xml:lang="en">Subgroups of populations based on age. (NCI)</TranslatedText>
        </Description>
        <EnumeratedItem CodedValue="ADOLESCENT (12-17 YEARS)" nciodm:ExtCodeID="C27954">
          <nciodm:CDISCDefinition>A juvenile between the onset of puberty and maturity; in the state of development between puberty and maturity. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Adolescent</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="ADULT (18-65)" nciodm:ExtCodeID="C49685">
          <nciodm:CDISCDefinition>A person from 18 years to 65 years of age. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Adult 18-65 Years Old</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="CHILDREN (2-11 YEARS)" nciodm:ExtCodeID="C49683">
          <nciodm:CDISCDefinition>A person from 2 years to 11 years of age. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Children 2-11 Years Old</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="ELDERLY (&gt; 65)" nciodm:ExtCodeID="C16268">
          <nciodm:CDISCDefinition>An age group comprised by people 65 years of age and older. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Elderly</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="IN UTERO" nciodm:ExtCodeID="C49641">
          <nciodm:CDISCDefinition>The period of time during which the embryo or fetus is present in the uterus of the female. Also describes the location of the embryo or fetus as being in the uterus in contrast to outside the uterus (ex utero). (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>In Utero</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="INFANT AND TODDLER (28 DAYS - 23 MONTHS)" nciodm:ExtCodeID="C49643">
          <nciodm:CDISCDefinition>A person from 28 days to 23 months of age. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Infant And Toddler</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="NEWBORN (0-27 DAYS)" nciodm:ExtCodeID="C16731">
          <nciodm:CDISCDefinition>An infant during the first month after birth. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Newborn</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="PRETERM NEWBORN INFANTS" nciodm:ExtCodeID="C49642">
          <nciodm:CDISCDefinition>An infant born prior to completion of the normal gestation period. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Preterm Newborn Infant</nciodm:PreferredTerm>
        </EnumeratedItem>
        <nciodm:CDISCSubmissionValue>AGESPAN</nciodm:CDISCSubmissionValue>
        <nciodm:CDISCSynonym>Age Span</nciodm:CDISCSynonym>
        <nciodm:PreferredTerm>CDISC SDTM Age Group Terminology</nciodm:PreferredTerm>
      </CodeList>
      <CodeList OID="CL.C66781.AGEU" Name="Age Unit" DataType="text" nciodm:ExtCodeID="C66781" nciodm:CodeListExtensible="No">
        <Description>
          <TranslatedText xml:lang="en">Those units of time that are routinely used to express the age of a person. (NCI)</TranslatedText>
        </Description>
        <EnumeratedItem CodedValue="DAYS" nciodm:ExtCodeID="C25301">
          <nciodm:CDISCDefinition>The time for Earth to make a complete rotation on its axis; ordinarily divided into twenty-four hours. This also refers to a specific day. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Day</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="HOURS" nciodm:ExtCodeID="C25529">
          <nciodm:CDISCDefinition>A unit measure of time equal to 3,600 seconds or 60 minutes. It is approximately 1/24 of a median day. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Hour</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="MONTHS" nciodm:ExtCodeID="C29846">
          <nciodm:CDISCDefinition>One of the 12 divisions of a year as determined by a calendar. It corresponds to the unit of time of approximately to one cycle of the moon's phases, about 30 days or 4 weeks. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Month</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="WEEKS" nciodm:ExtCodeID="C29844">
          <nciodm:CDISCDefinition>Any period of seven consecutive days. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Week</nciodm:PreferredTerm>
        </EnumeratedItem>
        <EnumeratedItem CodedValue="YEARS" nciodm:ExtCodeID="C29848">
          <nciodm:CDISCDefinition>The period of time that it takes for Earth to make a complete revolution around the sun, approximately 365 days; a specific one year period. (NCI)</nciodm:CDISCDefinition>
          <nciodm:PreferredTerm>Year</nciodm:PreferredTerm>
        </EnumeratedItem>
        <nciodm:CDISCSubmissionValue>AGEU</nciodm:CDISCSubmissionValue>
        <nciodm:CDISCSynonym>Age Unit</nciodm:CDISCSynonym>
        <nciodm:PreferredTerm>CDISC SDTM Age Unit Terminology</nciodm:PreferredTerm>
      </CodeList>
    </MetaDataVersion>
  </Study>
</ODM>

---

这个小脚本就可以做到这一点

from lxml import etree
# parse the file
root = etree.parse("/home/me/tmp/test.xml")

# important! register default namespace (i.e. no prefix) with a prefix, h in this case
ns = {"h" : "http://www.cdisc.org/ns/odm/v1.3"}

# get a single element for a particular OID
# cl = root.xpath("//h:CodeList[@OID='CL.C66767.ACN']", namespaces=ns)

# get the list of elements
cl = root.xpath("//h:CodeList", namespaces=ns)

for t in cl:
    # get the attribute value
    att = t.xpath("./@OID")
    print(att[0])
    # get the element tree
    et = etree.ElementTree(t)
    # write it to file
    et.write(att[0] + '.OUT', pretty_print=True)

一般来说，它比ElementTree好，并且没有必要将它们混合在一起

etree提供了更多的功能，如XPath、XSLT、RELAXNG和XML模式支持，而ElementTree不提供这些功能

---

这个小脚本就可以做到这一点

from lxml import etree
# parse the file
root = etree.parse("/home/me/tmp/test.xml")

# important! register default namespace (i.e. no prefix) with a prefix, h in this case
ns = {"h" : "http://www.cdisc.org/ns/odm/v1.3"}

# get a single element for a particular OID
# cl = root.xpath("//h:CodeList[@OID='CL.C66767.ACN']", namespaces=ns)

# get the list of elements
cl = root.xpath("//h:CodeList", namespaces=ns)

for t in cl:
    # get the attribute value
    att = t.xpath("./@OID")
    print(att[0])
    # get the element tree
    et = etree.ElementTree(t)
    # write it to file
    et.write(att[0] + '.OUT', pretty_print=True)

一般来说，它比ElementTree好，并且没有必要将它们混合在一起

etree提供了更多的功能，如XPath、XSLT、RELAXNG和XML模式支持，而ElementTree不提供这些功能

---

你的代码在哪里？你的代码在哪里？这正按照预期工作。你太棒了！非常感谢你。我现在将能够跟踪这些XML文档的发展。很高兴听到这个消息，如果你愿意，你也可以接受答案。@LuisMuñoz，你有“lxml优于ElementTree”的来源吗？可能对OP（还有我！）了解这些差异并理解如何更好地使用它们很有用。@Tim重新措辞了陈述并添加了一个链接，希望能有所帮助。这完全符合预期。你太棒了！非常感谢你。我现在将能够跟踪这些XML文档的发展。很高兴听到这个消息，如果你愿意，你也可以接受答案。@LuisMuñoz，你有“lxml优于ElementTree”的来源吗？对于OP（还有我！）来说，阅读这些差异并理解如何更好地使用可能会很有用。@Tim重新措辞了这句话，并添加了一个链接，希望能有所帮助。

from lxml import etree
# parse the file
root = etree.parse("/home/me/tmp/test.xml")

# important! register default namespace (i.e. no prefix) with a prefix, h in this case
ns = {"h" : "http://www.cdisc.org/ns/odm/v1.3"}

# get a single element for a particular OID
# cl = root.xpath("//h:CodeList[@OID='CL.C66767.ACN']", namespaces=ns)

# get the list of elements
cl = root.xpath("//h:CodeList", namespaces=ns)

for t in cl:
    # get the attribute value
    att = t.xpath("./@OID")
    print(att[0])
    # get the element tree
    et = etree.ElementTree(t)
    # write it to file
    et.write(att[0] + '.OUT', pretty_print=True)