htmlTree

Синтаксический HTML

Описание

Система координат htmlTree объект представляет проанализированный HTML элемента или узел. Извлечение интересующих частей с помощью findElement функцию или Children свойство и извлечение текста с помощью extractHTMLText функция.

Создание

Синтаксис

Описание

пример

tree = htmlTree(code) анализирует HTML кода в строке code и возвращает получившуюся древовидную структуру.

Входные параметры

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HTML кода, заданная как строковые массивы, вектор символов или массив ячеек векторов символов.

Совет

  • Чтобы считать HTML кода с веб-страницы, используйте webread.

  • Чтобы извлечь текст из HTML файла, используйте extractFileText.

Пример: "<a href='https://www.mathworks.com'>MathWorks</a>"

Типы данных: char | string | cell

Свойства

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Прямые потомки элемента, заданные как htmlTree массив.

Родительский узел в дереве, заданный как htmlTree объект.

Если HTML является корневым узлом, то значение Parent является missing.

Имя элемента HTML, заданное как строковый скаляр.

Для получения дополнительной информации см. раздел Элементы HTML.

Функции объекта

findElementПоиск элементов в HTML
getAttributeЧтение HTML корневого узла HTML
extractHTMLTextИзвлечение текста из HTML
ismissingПоиск HTML без значений

Примеры

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Чтение HTML кода из URL- https://www.mathworks.com/help/textanalytics использование webread.

url = "https://www.mathworks.com/help/textanalytics";
code = webread(url);

Проанализируйте HTML кода с помощью htmlTree.

tree = htmlTree(code);

Просмотрите имя элемента корневого узла дерева.

tree.Name
ans = 
"HTML"

Просмотрите дочерние элементы корневого узла.

tree.Children
ans = 
  4×1 htmlTree:

    " "
    <HEAD><TITLE>Text Analytics Toolbox Documentation</TITLE><META charset="utf-8"/><META content="width=device-width, initial-scale=1.0" name="viewport"/><META content="IE=edge" http-equiv="X-UA-Compatible"/><LINK href="/includes_content/responsive/css/bootstrap/bootstrap.min.css" rel="stylesheet" type="text/css"/><LINK href="/includes_content/responsive/css/site6.css?201903" rel="stylesheet" type="text/css"/><LINK href="/includes_content/responsive/css/site6_lg.css?201903" media="screen and (min-width: 1200px)" rel="stylesheet"/><LINK href="/includes_content/responsive/css/site6_md.css?201903" media="screen and (min-width: 992px) and (max-width: 1199px)" rel="stylesheet"/><LINK href="/includes_content/responsive/css/site6_sm+xs.css?201903" media="screen and (max-width: 991px)" rel="stylesheet"/><LINK href="/includes_content/responsive/css/site6_sm.css?201903" media="screen and (min-width: 768px) and (max-width: 991px)" rel="stylesheet"/><LINK href="/includes_content/responsive/css/site6_…
    " "
    <BODY id="responsive_offcanvas"><!-- Mobile TopNav: Start --><DIV class="header visible-xs visible-sm" id="header_mobile" translate="no"><NAV class="navbar navbar-default" role="navigation"><DIV class="container-fluid"><DIV class="row"><DIV class="col-xs-12"><DIV class="navbar-header"><BUTTON class="navbar-toggle topnav_toggle" data-target="#topnav_collapse" data-toggle="collapse" type="button"><SPAN class="sr-only">Toggle Main Navigation</SPAN><SPAN class="icon-menu"/></BUTTON><A class="svg_link navbar-brand" href="https://www.mathworks.com?s_tid=gn_logo"><IMG alt="MathWorks" class="mw_logo" src="/images/responsive/global/pic-header-mathworks-logo.svg"/></A></DIV></DIV></DIV><DIV class="row visible-xs visible-sm"><DIV class="col-xs-12"><DIV class="navbar-collapse collapse" id="topnav_collapse"><UL class="nav navbar-nav" id="topnav"><LI class="headernav_login"><A class="mwa-nav_login" href="https://www.mathworks.com/login?uri=http://www.mathworks.com/help/textanalytics/index.html">Sign…

Извлечение текста из HTML с помощью extractHTMLText.

str = extractHTMLText(tree)
str = 
    "Text Analytics Toolbox™ provides algorithms and visualizations for preprocessing, analyzing, and modeling text data. Models created with the toolbox can be used in applications such as sentiment analysis, predictive maintenance, and topic modeling.
     
     Text Analytics Toolbox includes tools for processing raw text from sources such as equipment logs, news feeds, surveys, operator reports, and social media. You can extract text from popular file formats, preprocess raw text, extract individual words, convert text into numerical representations, and build statistical models.
     
     Using machine learning techniques such as LSA, LDA, and word embeddings, you can find clusters and create features from high-dimensional text datasets. Features created with Text Analytics Toolbox can be combined with features from other data sources to build machine learning models that take advantage of textual, numeric, and other types of data."

Чтение HTML кода из URL- https://www.mathworks.com/help/textanalytics использование webread функция.

url = "https://www.mathworks.com/help/textanalytics";
code = webread(url);

Проанализируйте HTML кода с помощью htmlTree.

tree = htmlTree(code);

Найти все гиперссылки в HTML можно используя findElement. Гиперссылки являются узлами с именем элемента "A".

selector = "A";
subtrees = findElement(tree,selector);

Просмотрите первые несколько поддеревьев.

subtrees(1:10)
ans = 
  10×1 htmlTree:

    <A class="skip_link sr-only" href="#content_container">Skip to content</A>
    <A href="https://www.mathworks.com?s_tid=gn_logo" class="svg_link navbar-brand"><IMG src="/images/responsive/global/pic-header-mathworks-logo.svg" class="mw_logo" alt="MathWorks"/></A>
    <A href="https://www.mathworks.com/products.html?s_tid=gn_ps">Products</A>
    <A href="https://www.mathworks.com/solutions.html?s_tid=gn_sol">Solutions</A>
    <A href="https://www.mathworks.com/academia.html?s_tid=gn_acad">Academia</A>
    <A href="https://www.mathworks.com/support.html?s_tid=gn_supp">Support</A>
    <A href="https://www.mathworks.com/matlabcentral/?s_tid=gn_mlc">Community</A>
    <A href="https://www.mathworks.com/company/events.html?s_tid=gn_ev">Events</A>
    <A href="https://www.mathworks.com/products/get-matlab.html?s_tid=gn_getml">Get MATLAB</A>
    <A href="https://www.mathworks.com?s_tid=gn_logo" class="svg_link pull-left"><IMG src="/images/responsive/global/pic-header-mathworks-logo.svg" class="mw_logo" alt="MathWorks"/></A>

Извлечь текст из поддеревьев можно используя extractHTMLText. Результат содержит текст ссылки из каждой ссылки на странице.

str = extractHTMLText(subtrees);
str(1:10)
ans = 10×1 string
    "Skip to content"
    ""
    "Products"
    "Solutions"
    "Academia"
    "Support"
    "Community"
    "Events"
    "Get MATLAB"
    ""

Чтение HTML кода из URL- https://www.mathworks.com/help/textanalytics использование webread.

url = "https://www.mathworks.com/help/textanalytics";
code = webread(url);

Проанализируйте HTML кода с помощью htmlTree.

tree = htmlTree(code);

Найти все гиперссылки в HTML можно используя findElement. Гиперссылки являются узлами с именем элемента "A".

selector = "A";
subtrees = findElement(tree,selector);
subtrees(1:10)
ans = 
  10×1 htmlTree:

    <A class="svg_link navbar-brand" href="https://www.mathworks.com?s_tid=gn_logo"><IMG alt="MathWorks" class="mw_logo" src="/images/responsive/global/pic-header-mathworks-logo.svg"/></A>
    <A class="mwa-nav_login" href="https://www.mathworks.com/login?uri=http://www.mathworks.com/help/textanalytics/index.html">Sign In</A>
    <A href="https://www.mathworks.com/products.html?s_tid=gn_ps">Products</A>
    <A href="https://www.mathworks.com/solutions.html?s_tid=gn_sol">Solutions</A>
    <A href="https://www.mathworks.com/academia.html?s_tid=gn_acad">Academia</A>
    <A href="https://www.mathworks.com/support.html?s_tid=gn_supp">Support</A>
    <A href="https://www.mathworks.com/matlabcentral/?s_tid=gn_mlc">Community</A>
    <A href="https://www.mathworks.com/company/events.html?s_tid=gn_ev">Events</A>
    <A href="https://www.mathworks.com/company/aboutus/contact_us.html?s_tid=gn_cntus">Contact Us</A>
    <A href="https://www.mathworks.com/store?s_cid=store_top_nav&amp;s_tid=gn_store">How to Buy</A>

Получите ссылки на гиперссылки с помощью getAttribute. Укажите имя атрибута "href".

attr = "href";
str = getAttribute(subtrees,attr);
str(1:10)
ans = 10×1 string array
    "https://www.mathworks.com?s_tid=gn_logo"
    "https://www.mathworks.com/login?uri=http://www.mathworks.com/help/textanalytics/index.html"
    "https://www.mathworks.com/products.html?s_tid=gn_ps"
    "https://www.mathworks.com/solutions.html?s_tid=gn_sol"
    "https://www.mathworks.com/academia.html?s_tid=gn_acad"
    "https://www.mathworks.com/support.html?s_tid=gn_supp"
    "https://www.mathworks.com/matlabcentral/?s_tid=gn_mlc"
    "https://www.mathworks.com/company/events.html?s_tid=gn_ev"
    "https://www.mathworks.com/company/aboutus/contact_us.html?s_tid=gn_cntus"
    "https://www.mathworks.com/store?s_cid=store_top_nav&s_tid=gn_store"

Чтение HTML кода из URL- https://www.mathworks.com/help/textanalytics использование webread функция.

url = "https://www.mathworks.com/help/textanalytics";
code = webread(url);

Проанализируйте HTML кода с помощью htmlTree функция.

tree = htmlTree(code);

Найдите все абзацы в HTML с помощью findElement функция. Абзацы являются узлами с именем элемента «P».

subtrees = findElement(tree,"P");

Преобразуйте поддеревья в строку с помощью string функция.

str = string(subtrees)
str = 26×1 string
    "<P class="h1">↵  <A href="../index.html" class="coming_from_product">Documentation</A>↵  <A href="../index.html" class="not_coming_from_product">Help Center</A>↵</P>"
    "<P>Text Analytics Toolbox™ provides algorithms and visualizations for preprocessing, analyzing, and modeling text data. Models created with the toolbox can be used in applications such as sentiment analysis, predictive maintenance, and topic modeling.</P>"
    "<P>Text Analytics Toolbox includes tools for processing raw text from sources such as equipment logs, news feeds, surveys, operator reports, and social media. You can extract text from popular file formats, preprocess raw text, extract individual words, convert text into numerical representations, and build statistical models.</P>"
    "<P>Using machine learning techniques such as LSA, LDA, and word embeddings, you can find clusters and create features from high-dimensional text datasets. Features created with Text Analytics Toolbox can be combined with features from other data sources to build machine learning models that take advantage of textual, numeric, and other types of data.</P>"
    "<P class="category_desc">Learn the basics of Text Analytics Toolbox</P>"
    "<P class="category_desc">Import text data into MATLAB<SUP>®</SUP> and preprocess it for analysis</P>"
    "<P class="category_desc">Develop predictive models using topic models and word embeddings</P>"
    "<P class="category_desc">Visualize text data and models using word clouds and text scatter plots</P>"
    "<P class="category_desc">Information on language support in Text Analytics Toolbox</P>"
    "<P>You clicked a link that corresponds to this MATLAB command:</P>"
    "<P>Run the command by entering it in the MATLAB Command Window. Web browsers do not support MATLAB commands.</P>"
    "<P>Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: <STRONG class="recommended-country"/>.</P>"
    "<P>You can also select a web site from the following list:</P>"
    "<P>Select the China site (in Chinese or English) for best site performance. Other MathWorks country sites are not optimized for visits from your location.</P>"
    "<P class="text-center">↵  <A href="#" class="worldwide_link">Contact your local office</A>↵</P>"
    "<P class="ff_section_title">Explore Products</P>"
    "<P class="ff_section_title">Try or Buy</P>"
    "<P class="ff_section_title">Learn to Use</P>"
    "<P class="ff_section_title">Get Support</P>"
    "<P class="ff_section_title">About <SPAN translate="no">MathWorks</SPAN></P>"
    "<P class="h4 add_font_futura_medium add_margin_0">↵  <SPAN translate="no">MathWorks</SPAN>↵</P>"
    "<P>↵  <EM>Accelerating the pace of engineering and science</EM>↵</P>"
    "<P><SPAN translate="no">MathWorks</SPAN> is the leading developer of mathematical computing software for engineers and scientists.</P>"
    "<P>↵  <A href="/discovery.html?s_tid=all_disc_mw_ff">Discover...</A>↵</P>"
    "<P class="copyright" translate="no">© 1994-2021 The MathWorks, Inc.</P>"
    "<P>↵  <EM>Join the conversation</EM>↵</P>"

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Вопросы совместимости

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Поведение изменено в R2021a

Введенный в R2018b
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