python - XPath:通过当前节点属性选择当前和下一个节点的文本

Question

首先，这是来自 my previous question 的衍生品。 .我再次发布此内容是因为 the person whose answer I accepted in the original post 建议我这样做因为他觉得这个问题以前没有正确定义。尝试2:

我正在尝试从 this webpage 中获取信息.为清楚起见，以下是 选择 页面源的 block :

<p class="titlestyle">ANT101H5 Introduction to Biological Anthropology and Archaeology 
                    <span class='distribution'>(SCI)</span></p> 
<span class='normaltext'> 
Anthropology is the global and holistic study of human biology and behaviour, and includes four subfields: biological anthropology, archaeology, sociocultural anthropology and linguistics. The material covered is  directed  to answering the question: What makes us human? This course is a survey of  biological  anthropology and  archaeology.  [<span class='Helpcourse'
        onMouseover="showtip(this,event,'24 Lectures')"
        onMouseout="hidetip()">24L</span>, <span class='Helpcourse'
        onMouseover="showtip(this,event,'12 Tutorials')"
        onMouseout="hidetip()">12T</span>]<br> 
<span class='title2'>Exclusion: </span><a href='javascript:OpenCourse("WEBCOURSENOTFOUND.html")'>ANT100Y5</a><br> 
<span class='title2'>Prerequisite: </span><a href='javascript:OpenCourse("WEBCOURSEANT102H5.pl?fv=1")'>ANT102H5</a><br> 

从上面的示例 block 中，我想提取以下信息:

ANT101H5 Introduction to Biological Anthropology and Archaeology

Exclusion: ANT100Y5

Prerequisite: ANT102H5

我想从网页上获取所有此类信息(请记住，某些类(class)可能还有额外列出的“共同要求”，或者可能根本没有列出任何先决条件/共同要求或排除项)。

我一直在尝试为此任务编写一个适当的 xpath 表达式，但我似乎无法做到恰到好处。

到目前为止，在 Dimitre Novatchev 的帮助下，我已经能够使用以下表达式:

sites = hxs.select("(//p[@class='titlestyle'])[2]/text()[1] | (//span[@class='title2'])[2]/text() | \
                    (//span[@class='title2'])[2]/following-sibling::a[1]/text() | (//span[@class='title2'])[3]/text() | \
                    (//span[@class='title2'])[3]/following-sibling::a[1]/text()")

但是，它会产生以下输出，似乎只获得了 的信息。第一个 页面上的类(class):

[{"desc": "ANT101H5 Introduction to Biological Anthropology and Archaeology \n                        "},
 {"desc": "Exclusion: "},
 {"desc": "ANT100Y5"},
 {"desc": "Prerequisite: "},
 {"desc": "ANT102H5"}]

绝对清楚，这个输出只有在它获得关于第一门类(class)的正确信息的情况下才是正确的。我需要这样的正确信息 全部 该网页上列出的类(class)。

我是如此接近，但我似乎无法弄清楚最后一步。

我会很感激任何帮助...在此先感谢

Answer 1

为所有类(class)选择相关数据所需的单个 XPath 表达式相当困惑 ，所以在这里我采用另一种方法，可以使用(如果有必要的话)生成单个 XPath 表达式:

这个简单的 XSLT 转换 :

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:strip-space elements="*"/>

 <xsl:template match="p[@class='titlestyle']">
  <xsl:text>&#xA;===================&#xA;</xsl:text>
  <xsl:value-of select="text()[1]"/>
 </xsl:template>

 <xsl:template match=
  "span/span[@class='title2'][not(position() >1)]">
   <xsl:text>&#xA;</xsl:text>
   <xsl:value-of select="."/>
   <xsl:value-of select="following-sibling::a[1]"/>

   <xsl:if test="not(following-sibling::a)">
    <xsl:value-of select="following-sibling::text()[1]"/>
   </xsl:if>
   <xsl:text>&#xA;</xsl:text>
 </xsl:template>
 <xsl:template match="text()"/>
</xsl:stylesheet>

在 的页面上应用时: http://www.utm.utoronto.ca/regcal/WEBLISTCOURSES1.html (整理成格式良好的 XML 文档)， 产生想要的结果 :

===================
Anthropology
===================
ANT101H5 Introduction to Biological Anthropology and Archaeology

Exclusion: ANT100Y5

===================
ANT102H5 Introduction to Sociocultural and Linguistic Anthropology

Exclusion: ANT100Y5

===================
ANT200Y5 World Archaeology and Prehistory

Prerequisite: 101H5

===================
ANT203Y5 Biological Anthropology

Prerequisite: 101H5

===================
ANT204Y5 Sociocultural Anthropology

Prerequisite: 101H5

===================
ANT205H5 Introduction to Forensic Anthropology

Prerequisite: 101H5

===================
ANT206Y5 Culture and Communication: Introduction to Linguistic Anthropology

Exclusion: ANT206H5

===================
ANT241Y5 Aboriginal Peoples of North America

===================
ANT299Y5 Research Opportunity Program

===================
ANT304H5 Anthropology and Aboriginal Peoples

Exclusion: ANT304Y5

===================
ANT306H5 Forensic Anthropology Field School

Prerequisite: ANT205H5

===================
ANT308H5 Case Studies in Archaeological Botany and Zoology

Prerequisite: ANT200Y5

===================
ANT309H5 Southeast Asian Archaeology

Prerequisite: ANT200Y5

===================
ANT310H5 Complex Societies

Prerequisite: ANT200Y5

===================
ANT312H5 Archaeological Analysis

Prerequisite: ANT200Y5

===================
ANT313H5 China, Korea and Japan in Prehistory

Prerequisite: ANT200Y5

===================
ANT314H5 Archaeological Theory

Exclusion: ANT411H5

===================
ANT316H5 South Asian Archaeology

Prerequisite: ANT200Y5

===================
ANT317H5 Archaeology of Eastern North America

Prerequisite: ANT200Y5

===================
ANT318H5 Archaeological Fieldwork

Prerequisite: ANT200Y5

===================
ANT320H5 Archaeological Approaches to Technology

Prerequisite: ANT200Y5

===================
ANT322H5 Anthropology of Youth Culture

Exclusion: ANT204Y5

===================
ANT327H5 Agricultural Origins:  The Second Revolution

Prerequisite: ANT200Y5

===================
ANT331H5 The Biology of Human Sexuality

Exclusion: ANT330H5

===================
ANT332H5 Human Origins

Exclusion: ANT332Y5

===================
ANT333H5 Human Origins II

Exclusion: ANT332Y5

===================
ANT334H5 Human Osteology

Exclusion: ANT334Y5

===================
ANT335H5 Anthropology of Gender

Exclusion: ANT331Y5

===================
ANT336H5 Molecular Anthropology

Prerequisite: ANT203Y5

===================
ANT338H5 Laboratory Methods in Biological Anthropology

Prerequisite: ANT203Y5

===================
ANT339Y5 Human Adaptation through Biological and Cultural Means

Prerequisite: ANT203Y5

===================
ANT340H5 Osteological Theory

Exclusion: ANT334Y5

===================
ANT350H5 Globalization and the Changing World of Work

Prerequisite: ANT204Y5

===================
ANT351H5 Money, Markets, Gifts: Topics in Economic Anthropology

Prerequisite: ANT204Y5

===================
ANT352H5 Power, Authority, and Legitimacy: Topics in Political Anthropology

Prerequisite: ANT204Y5

===================
ANT358H5 Ethnographic Methods

Prerequisite: ANT204Y5

===================
ANT360H5 Anthropology of Religion

Exclusion: ANT209Y5

===================
ANT361H5 Anthropology of Sub-Saharan Africa

Exclusion: ANT212Y5

===================
ANT362H5 Language in Culture and Society

Prerequisite: ANT204Y5

===================
ANT363H5 Magic, Witchcraft and Science

Prerequisite: ANT360H5

===================
ANT364H5 Lab in Social Interaction

Prerequisite: ANT206H5

===================
ANT365H5 Semiotic Anthropology

Prerequisite: ANT204Y5

===================
ANT368H5 World Religions and Ecology

Exclusion: RLG311H5

===================
ANT369H5 Religious Violence and Nonviolence

Exclusion: RLG317H5

===================
ANT397H5 Independent Study

Prerequisite: Permission of Faculty Advisor


===================
ANT398Y5 Independent Reading

Prerequisite: Permission of Faculty Advisor


===================
ANT399Y5 Research Opportunity Program

Prerequisite: P.I.


===================
ANT401H5 Vocal and Visual Communication

Prerequisite: ANT102H5

===================
ANT414H5 People and Plants in Prehistory

Prerequisite: ANT200Y5

===================
ANT415H5 Faunal Archaeo-Osteology

Exclusion: ANT415Y5

===================
ANT416H5 Advanced Archaeological Analysis

Prerequisite: ANT312H5

===================
ANT418H5 Advanced Archaeological Fieldwork

Prerequisite: ANT318H5

===================
ANT430H5 Special Problems in Biological Anthropology and Archaeology

Prerequisite: P.I


===================
ANT430Y5 Special Problems in Biological Anthropology and Archaeology

Prerequisite: P.I. 


===================
ANT431Y5 Special Problems in Sociocultural or Linguistic Anthropology

Prerequisite: P.I.


===================
ANT431H5 Special Problems in Sociocultural or Linguistic Anthropology

Prerequisite: P.I.


===================
ANT432H5 Special Seminar in Anthropology

Prerequisite: P.I.


===================
ANT433H5 Genes, Language, Artifact and Mind

Prerequisite: ANT200Y5

===================
ANT434H5 Palaeopathology

Prerequisite: ANT334Y5

===================
ANT438H5 The Development of Thought in Biological Anthropology

Prerequisite: ANT203Y5

===================
ANT439Y5 Advanced Forensic Anthropology

Prerequisite: ANT205H5

===================
ANT441H5 Advanced Bioarchaeology

Prerequisite: ANT334H5

===================
ANT457H5 Anthropology and the Environment

Prerequisite: ANT102H5

===================
ANT458H5 Anthropology of Crime, Law and Order

Exclusion: ANT204Y5

===================
ANT459H5 The Ethnography of Speaking

Prerequisite: ANT206Y5

===================
ANT460H5 Theory in Sociocultural Anthropology

Prerequisite: ANT204Y5

===================
ANT461H5 Emergent Topics in Socio-Cultural &  Linguistic Anthropology

Prerequisite: ANT204Y5

===================
ANT498H5 Advanced Independent Study

Prerequisite: P.I.


===================
ANT499Y5 Advanced Independent Research

Prerequisite: P.I.