2

首先,这是我之前的问题的产物。我再次发布此消息是因为我在原始帖子中接受了其答案的人建议我这样做,因为他认为该问题以前没有正确定义。尝试2:

我正在尝试从此网页中获取信息。为清楚起见,以下是页面源代码块的选择:

<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> 


从上面的示例块中,我想提取以下信息:

  1. ANT101H5 Introduction to Biological Anthropology and Archaeology
  2. Exclusion: ANT100Y5
  3. Prerequisite: ANT102H5

我想从网页上获取所有此类信息(请记住,某些课程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,似乎只获取页面上第一门课程的信息:

[{"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课程的正确信息的情况下才是正确的。对于该网页上列出的所有课程,我需要这样的正确信息。

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

4

2 回答 2

2

为所有课程选择相关数据所需的单个 XPath 表达式非常混乱,所以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>

当在页面上应用时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 &amp;  Linguistic Anthropology

Prerequisite: ANT204Y5

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

Prerequisite: P.I.


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

Prerequisite: P.I.
于 2011-03-06T16:56:33.000 回答
0

尝试而不是[<int>]使用类似的东西[position() mod <offset> = <base>]

偏移量是您感兴趣的每个节点之间的距离。@class='titlestyle' 和 @class='title2' 可能不同。

ites = hxs.select("(//p[@class='titlestyle'])[position() mod <offset to next to match> = 2]/text()[1] | (//span[@class='title2'])[position() mod <offset to next to match> = 2]/text() | \
                    (//span[@class='title2'])[position() mod <offset to next to match> = 2]/following-sibling::a[1]/text() | (//span[@class='title2'])[position() mod <offset to next to match> = 3]/text() | \
                    (//span[@class='title2'])[position() mod <offset to next to match> = 3]/following-sibling::a[1]/text()")

编辑:根据要求。

一次执行每个单独的 xpath,而不限制其位置。这是一项手动事实调查练习,用于确定要在 xpath 中使用的最终值。

返回与以下 xpath 匹配的所有节点(这是第一个)。

ites = hxs.select("(//p[@class='titlestyle'])/text()[1]")

ites将包含一些你想要的课程和一些你不想要的。

您已经为此确定了第二个节点是您想要的第一个节点。ites现在计算到您希望此规则匹配的下一个的距离。这就是我们可以称之为的<offset to next to match>

现在对每个剩余的 xpath 搜索重复上述操作。

将 hxs.select("") 视为过滤器,并且在遍历 xml 时,将返回与您的 xpath 匹配的每一件事。

这是一个示例http://zvon.org/xxl/XPathTutorial/Output/example22.html

于 2011-03-06T07:22:30.507 回答