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python【模块】xml.etree.ElementTree 解析 xml
pytho 模块 xml.etree.ElementTree 解析 xml
1. 什么是 XML？
XML 代表可扩展标记语言。它在外观上类似于HTML，但 XML 用于数据表示，而 HTML 用于定义正在使用的数据。XML 专门设计用于在客户端和服务器之间来回发送和接收数据。
XML 创建了一种易于解释并支持层次结构的树状结构。只要页面遵循 XML，就可以将其称为 XML 文档。
- XML 文档具有称为元素的部分，由开始和结束标记定义。标签是一种以 开头
<和结尾的标记结构>。开始标签和结束标签之间的字符（如果有的话）是元素的内容。元素可以包含标记，包括其他元素，称为“子元素”。 - 最大的顶级元素称为root，它包含所有其他元素。
- 属性是存在于起始标签或空元素标签中的名称-值对。XML 属性只能有一个值，并且每个属性在每个元素上最多只能出现一次。
XML 文件:
<?xml version="1.0"?> <collection> <genre category="Action"> <decade years="1980s"> <movie favorite="True" title="Indiana Jones: The raiders of the lost Ark"> <format multiple="No">DVD</format> <year>1981</year> <rating>PG</rating> <description> 'Archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before the Nazis.' </description> </movie> <movie favorite="True" title="THE KARATE KID"> <format multiple="Yes">DVD,Online</format> <year>1984</year> <rating>PG</rating> <description>None provided.</description> </movie> <movie favorite="False" title="Back 2 the Future"> <format multiple="False">Blu-ray</format> <year>1985</year> <rating>PG</rating> <description>Marty McFly</description> </movie> </decade> <decade years="1990s"> <movie favorite="False" title="X-Men"> <format multiple="Yes">dvd, digital</format> <year>2000</year> <rating>PG-13</rating> <description>Two mutants come to a private academy for their kind whose resident superhero team must oppose a terrorist organization with similar powers.</description> </movie> <movie favorite="True" title="Batman Returns"> <format multiple="No">VHS</format> <year>1992</year> <rating>PG13</rating> <description>NA.</description> </movie> <movie favorite="False" title="Reservoir Dogs"> <format multiple="No">Online</format> <year>1992</year> <rating>R</rating> <description>WhAtEvER I Want!!!?!</description> </movie> </decade> </genre> <genre category="Thriller"> <decade years="1970s"> <movie favorite="False" title="ALIEN"> <format multiple="Yes">DVD</format> <year>1979</year> <rating>R</rating> <description>"""""""""</description> </movie> </decade> <decade years="1980s"> <movie favorite="True" title="Ferris Bueller's Day Off"> <format multiple="No">DVD</format> <year>1986</year> <rating>PG13</rating> <description>Funny movie about a funny guy</description> </movie> <movie favorite="FALSE" title="American Psycho"> <format multiple="No">blue-ray</format> <year>2000</year> <rating>Unrated</rating> <description>psychopathic Bateman</description> </movie> </decade> </genre>- 1
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从您上面阅读的内容中，您可以看到
- 这些子元素也可以充当父元素并包含它们自己的子元素，这些子元素称为“子子元素”。例如，您会看到
2. ElementTree 简介
到目前为止，您所了解的 XML 解析器可以完成这项工作。但是，它们不太符合 Python 的哲学，这绝非偶然。虽然 DOM 遵循 W3C 规范，而 SAX 是根据 Java API 建模的，但两者都没有特别像 Python 的感觉。
更糟糕的是，DOM 和 SAX 解析器都感觉过时了，因为它们在CPython解释器中的一些代码已经超过 20 年没有改变了！在撰写本文时，它们的实现仍然不完整，并且缺少 typeshed 存根，这会破坏代码编辑器中的代码完成。
同时，Python 2.5 带来了解析和编写 XML 文档的全新视角——
ElementTree API。它是一个轻量级、高效、优雅且功能丰富的界面，甚至一些第三方库也以此为基础。要开始使用它，您必须导入xml.etree.ElementTree模块，这有点拗口。因此，习惯上这样定义别名：import xml.etree.ElementTree as ET- 1
您可以通过采用不同的解析策略来使用 ElementTree API：
非增量 增量（阻塞） 增量（非阻塞） ET.parse() ✔️ ET.fromstring() ✔️ ET.iterparse() ✔️ ET.XMLPullParser ✔️ 3. 解析 XML 数据
提供的 XML 文件中，有一个描述的电影的基本集合。唯一的问题是数据很乱！这个集合有很多不同的策展人，每个人都有自己的方式将数据输入文件。本教程的主要目标是使用 Python 阅读和理解文件 - 然后解决问题。
首先，您需要使用
ElementTree.tree = ET.parse('movies.xml') root = tree.getroot()- 1
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现在您已经初始化了树，您应该查看 XML 并打印出值以了解树的结构。
树的每个部分（包括根）都有一个描述元素的标签。此外，正如您在介绍中看到的那样，元素可能具有属性，这些属性是附加的描述符，特别用于重复标记的使用。属性还有助于验证为该标记输入的值，再次有助于 XML 的结构化格式。
root.tag 输出： 'collection'- 1
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在顶层，您会看到此 XML 植根于collection标记中。
root.attrib 输出： {}- 1
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所以根没有属性。
示例
xml:
<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd" [ <!ENTITY custom_entity "Hello"> ]> <svg xmlns="http://www.w3.org/2000/svg" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" viewBox="-105 -100 210 270" width="210" height="270"> <inkscape:custom x="42" inkscape:z="555">Some value</inkscape:custom> <defs> <linearGradient id="skin" x1="0" x2="0" y1="0" y2="1"> <stop offset="0%" stop-color="yellow" stop-opacity="1.0"/> <stop offset="75%" stop-color="gold" stop-opacity="1.0"/> <stop offset="100%" stop-color="orange" stop-opacity="1"/> </linearGradient> </defs> <g id="smiley" inkscape:groupmode="layer" inkscape:label="Smiley"> <!-- Head --> <circle cx="0" cy="0" r="50" fill="url(#skin)" stroke="orange" stroke-width="2"/> <!-- Eyes --> <ellipse cx="-20" cy="-10" rx="6" ry="8" fill="black" stroke="none"/> <ellipse cx="20" cy="-10" rx="6" ry="8" fill="black" stroke="none"/> <!-- Mouth --> <path d="M-20 20 A25 25 0 0 0 20 20" fill="white" stroke="black" stroke-width="3"/> </g> <text x="-40" y="75">&custom_entity; <svg>!</text> <script> <![CDATA[ console.log("CDATA disables XML parsing: ) const smiley = document.getElementById("smiley") const eyes = document.querySelectorAll("ellipse") const setRadius = r => e => eyes.forEach(x => x.setAttribute("ry", r)) smiley.addEventListener("mouseenter", setRadius(2)) smiley.addEventListener("mouseleave", setRadius(8)) ]]> </script> </svg>- 1
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>>> import xml.etree.ElementTree as ET >>> tree = ET.parse('movies.xml') >>> root = tree.getroot() >>> element = root[0] >>> element.tag '{http://www.inkscape.org/namespaces/inkscape}custom' >>> element.text 'Some value' >>> element.attrib {'x': '42', '{http://www.inkscape.org/namespaces/inkscape}z': '555'} >>> element.get("x") '42'- 1
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4. For 循环
通过使用简单的“for”循环，您可以轻松地迭代根中的子元素（通常称为“子元素”）。
for child in root: print(child.tag, child.attrib)- 1
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输出：
genre {'category': 'Action'} genre {'category': 'Thriller'} genre {'category': 'Comedy'}- 1
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现在你知道根的孩子
collection都是genre. 为了指定类型，XML 使用属性category。genre根据元素，有Action,Thriller, andComedymovies。通常，了解整个树中的所有元素会很有帮助。一个有用的功能是
root.iter()。您可以将此函数放入“for”循环中，它将遍历整个树。[elem.tag for elem in root.iter()]- 1
输出：
['collection', 'genre', 'decade', 'movie', 'format', 'year', 'rating', 'description', 'movie', 'format', 'year', 'rating', 'description', 'movie', 'format', 'year', 'rating', 'description', 'decade', 'movie', 'format', 'year', 'rating', 'description', 'movie', 'format', 'year', 'rating', 'description', 'movie', 'format', 'year', 'rating', 'description', 'genre', 'decade', 'movie', 'format', 'year', 'rating', 'description', 'decade', 'movie', 'format', 'year', 'rating', 'description', 'movie', 'format', 'year', 'rating', 'description', 'genre', 'decade', 'movie', 'format', 'year', 'rating', 'description', 'decade', 'movie', 'format', 'year', 'rating', 'description', 'movie', 'format', 'year', 'rating', 'description', 'decade', 'movie', 'format', 'year', 'rating', 'description', 'decade', 'movie', 'format', 'year', 'rating', 'description']- 1
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这给出了您拥有多少个元素的一般概念，但它不显示树中的属性或级别。
有一种有用的方法可以查看整个文档。任何元素都有
.tostring()方法。如果将根传递给.tostring()方法，则可以返回整个文档。在ElementTree（记住别名为ET）内，.tostring()采用一种稍微奇怪的形式。由于ElementTree它是一个功能强大的库，不仅可以解释 XML，因此您必须将要显示的文档的编码和解码都指定为字符串。对于 XML，使用’
utf8’- 这是 XML 的典型文档格式类型。print(ET.tostring(root, encoding='utf8').decode('utf8'))- 1
输出：
<?xml version='1.0' encoding='utf8'?> <collection> <genre category="Action"> <decade years="1980s"> <movie favorite="True" title="Indiana Jones: The raiders of the lost Ark"> <format multiple="No">DVD</format> <year>1981</year> <rating>PG</rating> <description> 'Archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before the Nazis.' </description> </movie> <movie favorite="True" title="THE KARATE KID"> <format multiple="Yes">DVD,Online</format> <year>1984</year> <rating>PG</rating> <description>None provided.</description> </movie> <movie favorite="False" title="Back 2 the Future"> <format multiple="False">Blu-ray</format> <year>1985</year> <rating>PG</rating> <description>Marty McFly</description> </movie> </decade> <decade years="1990s"> <movie favorite="False" title="X-Men"> <format multiple="Yes">dvd, digital</format> <year>2000</year> <rating>PG-13</rating> <description>Two mutants come to a private academy for their kind whose resident superhero team must oppose a terrorist organization with similar powers.</description> </movie> <movie favorite="True" title="Batman Returns"> <format multiple="No">VHS</format> <year>1992</year> <rating>PG13</rating> <description>NA.</description> </movie> <movie favorite="False" title="Reservoir Dogs"> <format multiple="No">Online</format> <year>1992</year> <rating>R</rating> <description>WhAtEvER I Want!!!?!</description> </movie> </decade> </genre> <genre category="Thriller"> <decade years="1970s"> <movie favorite="False" title="ALIEN"> <format multiple="Yes">DVD</format> <year>1979</year> <rating>R</rating> <description>"""""""""</description> </movie> </decade> <decade years="1980s"> <movie favorite="True" title="Ferris Bueller's Day Off"> <format multiple="No">DVD</format> <year>1986</year> <rating>PG13</rating> <description>Funny movie about a funny guy</description> </movie> <movie favorite="FALSE" title="American Psycho"> <format multiple="No">blue-ray</format> <year>2000</year> <rating>Unrated</rating> <description>psychopathic Bateman</description> </movie> </decade> </genre> <genre category="Comedy"> <decade years="1960s"> <movie favorite="False" title="Batman: The Movie"> <format multiple="Yes">DVD,VHS</format> <year>1966</year> <rating>PG</rating> <description>What a joke!</description> </movie> </decade> <decade years="2010s"> <movie favorite="True" title="Easy A"> <format multiple="No">DVD</format> <year>2010</year> <rating>PG--13</rating> <description>Emma Stone = Hester Prynne</description> </movie> <movie favorite="True" title="Dinner for SCHMUCKS"> <format multiple="Yes">DVD,digital,Netflix</format> <year>2011</year> <rating>Unrated</rating> <description>Tim (Rudd) is a rising executive who “succeeds” in finding the perfect guest, IRS employee Barry (Carell), for his boss’ monthly event, a so-called “dinner for idiots,” which offers certain advantages to the exec who shows up with the biggest buffoon. </description> </movie> </decade> <decade years="1980s"> <movie favorite="False" title="Ghostbusters"> <format multiple="No">Online,VHS</format> <year>1984</year> <rating>PG</rating> <description>Who ya gonna call?</description> </movie> </decade> <decade years="1990s"> <movie favorite="True" title="Robin Hood: Prince of Thieves"> <format multiple="No">Blu_Ray</format> <year>1991</year> <rating>Unknown</rating> <description>Robin Hood slaying</description> </movie> </decade> </genre> </collection>- 1
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您可以扩展该
iter()函数的使用，以帮助查找感兴趣的特定元素。root.iter()将列出根下与指定元素匹配的所有子元素。在这里，您将列出movie树中元素的所有属性：for movie in root.iter('movie'): print(movie.attrib)- 1
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输出：
{'favorite': 'True', 'title': 'Indiana Jones: The raiders of the lost Ark'} {'favorite': 'True', 'title': 'THE KARATE KID'} {'favorite': 'False', 'title': 'Back 2 the Future'} {'favorite': 'False', 'title': 'X-Men'} {'favorite': 'True', 'title': 'Batman Returns'} {'favorite': 'False', 'title': 'Reservoir Dogs'} {'favorite': 'False', 'title': 'ALIEN'} {'favorite': 'True', 'title': "Ferris Bueller's Day Off"} {'favorite': 'FALSE', 'title': 'American Psycho'} {'favorite': 'False', 'title': 'Batman: The Movie'} {'favorite': 'True', 'title': 'Easy A'} {'favorite': 'True', 'title': 'Dinner for SCHMUCKS'} {'favorite': 'False', 'title': 'Ghostbusters'} {'favorite': 'True', 'title': 'Robin Hood: Prince of Thieves'}- 1
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您已经可以看到如何movies以不同的方式输入。暂时不用担心，稍后您将有机会在本教程中修复其中一个错误。
5. XPath 表达式
多时候元素没有属性，它们只有文本内容。使用属性
.text，您可以打印出此内容。现在，打印出电影的所有描述。
for description in root.iter('description'): print(description.text)- 1
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输出：
'Archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before the Nazis.' None provided. Marty McFly Two mutants come to a private academy for their kind whose resident superhero team must oppose a terrorist organization with similar powers. NA. WhAtEvER I Want!!!?! """"""""" Funny movie about a funny guy psychopathic Bateman What a joke! Emma Stone = Hester Prynne Tim (Rudd) is a rising executive who “succeeds” in finding the perfect guest, IRS employee Barry (Carell), for his boss’ monthly event, a so-called “dinner for idiots,” which offers certain advantages to the exec who shows up with the biggest buffoon. Who ya gonna call? Robin Hood slaying- 1
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打印出 XML 是有帮助的，但 XPath 是一种用于快速轻松地搜索 XML 的查询语言。XPath 代表 XML 路径语言，顾名思义，它使用“类似路径”的语法来识别和导航 XML 文档中的节点。
了解 XPath 对于扫描和填充 XML 至关重要。
ElementTree有一个.findall()函数将遍历被引用元素的直接子元素。您可以使用 XPath 表达式来指定更有用的搜索。在这里，您将在树中搜索 1992 年上映的电影：
for movie in root.findall("./genre/decade/movie/[year='1992']"): print(movie.attrib)- 1
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输出：
{'favorite': 'True', 'title': 'Batman Returns'} {'favorite': 'False', 'title': 'Reservoir Dogs'}- 1
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该函数
.findall()总是从指定的元素开始。这种类型的功能对于“查找和替换”来说非常强大。您甚至可以搜索属性！现在，仅打印以多种格式（属性）可用的电影。
for movie in root.findall("./genre/decade/movie/format/[@multiple='Yes']"): print(movie.attrib)- 1
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输出：
{'multiple': 'Yes'} {'multiple': 'Yes'} {'multiple': 'Yes'} {'multiple': 'Yes'} {'multiple': 'Yes'}- 1
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集思广益，为什么在这种情况下 print 语句会返回multiple. 想想“for”循环是如何定义的。你能改写这个循环来打印出电影标题吗？在下面试试：
提示：使用’…'inside XPath 返回当前元素的父元素。
for movie in root.findall("./genre/decade/movie/format[@multiple='Yes']..."): print(movie.attrib)- 1
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输出：
{'favorite': 'True', 'title': 'THE KARATE KID'} {'favorite': 'False', 'title': 'X-Men'} {'favorite': 'False', 'title': 'ALIEN'} {'favorite': 'False', 'title': 'Batman: The Movie'} {'favorite': 'True', 'title': 'Dinner for SCHMUCKS'}- 1
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6. 修改 XML
早些时候，电影标题绝对是一团糟。现在，再次打印出来：
for movie in root.iter('movie'): print(movie.attrib)- 1
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修复
Back 2 the Future中的“2”。这应该是一个查找和替换的问题。编写代码以查找标题“Back 2 the Future”并将其保存为变量：b2tf = root.find("./genre/decade/movie[@title='Back 2 the Future']") print(b2tf)- 1
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输出：
<Element 'movie' at 0x10ce00ef8>- 1
请注意，使用该
.find()方法会返回树的一个元素。很多时候，编辑元素内的内容更有用。修改title
Back 2 the Future元素变量的属性为“Back to the Future”。然后，打印出变量的属性以查看您的更改。您可以通过访问元素的属性然后为其分配新值来轻松地做到这一点：b2tf.attrib["title"] = "Back to the Future" print(b2tf.attrib)- 1
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输出：
{'favorite': 'False', 'title': 'Back to the Future'}- 1
将您的更改写回
XML，以便它们永久固定在文档中。再次打印您的电影属性以确保您的更改有效。使用.write()方法来做到这一点：tree.write("movies.xml") tree = ET.parse('movies.xml') root = tree.getroot() for movie in root.iter('movie'): print(movie.attrib)- 1
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输出：
{'favorite': 'True', 'title': 'Indiana Jones: The raiders of the lost Ark'} {'favorite': 'True', 'title': 'THE KARATE KID'} {'favorite': 'False', 'title': 'Back to the Future'} {'favorite': 'False', 'title': 'X-Men'} {'favorite': 'True', 'title': 'Batman Returns'} {'favorite': 'False', 'title': 'Reservoir Dogs'} {'favorite': 'False', 'title': 'ALIEN'} {'favorite': 'True', 'title': "Ferris Bueller's Day Off"} {'favorite': 'FALSE', 'title': 'American Psycho'} {'favorite': 'False', 'title': 'Batman: The Movie'} {'favorite': 'True', 'title': 'Easy A'} {'favorite': 'True', 'title': 'Dinner for SCHMUCKS'} {'favorite': 'False', 'title': 'Ghostbusters'} {'favorite': 'True', 'title': 'Robin Hood: Prince of Thieves'}- 1
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7. 修复属性
该
multiple属性在某些地方不正确。用于ElementTree根据影片进入的格式来修复指示符。首先，打印format属性和text以查看需要修复的部分。for form in root.findall("./genre/decade/movie/format"): print(form.attrib, form.text)- 1
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输出：
{'multiple': 'No'} DVD {'multiple': 'Yes'} DVD,Online {'multiple': 'False'} Blu-ray {'multiple': 'Yes'} dvd, digital {'multiple': 'No'} VHS {'multiple': 'No'} Online {'multiple': 'Yes'} DVD {'multiple': 'No'} DVD {'multiple': 'No'} blue-ray {'multiple': 'Yes'} DVD,VHS {'multiple': 'No'} DVD {'multiple': 'Yes'} DVD,digital,Netflix {'multiple': 'No'} Online,VHS {'multiple': 'No'} Blu_Ray- 1
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在这个标签上需要做一些工作。
您可以使用正则表达式查找逗号 - 这将判断
multiple属性应该是“是”还是“否”。.set()使用该方法可以轻松地添加和修改属性。注意：re是 Python 的标准正则表达式解释器。如果您想了解更多关于正则表达式的信息，请考虑本教程。
import re for form in root.findall("./genre/decade/movie/format"): # Search for the commas in the format text match = re.search(',',form.text) if match: form.set('multiple','Yes') else: form.set('multiple','No') # Write out the tree to the file again tree.write("movies.xml") tree = ET.parse('movies.xml') root = tree.getroot() for form in root.findall("./genre/decade/movie/format"): print(form.attrib, form.text)- 1
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输出：
{'multiple': 'No'} DVD {'multiple': 'Yes'} DVD,Online {'multiple': 'No'} Blu-ray {'multiple': 'Yes'} dvd, digital {'multiple': 'No'} VHS {'multiple': 'No'} Online {'multiple': 'No'} DVD {'multiple': 'No'} DVD {'multiple': 'No'} blue-ray {'multiple': 'Yes'} DVD,VHS {'multiple': 'No'} DVD {'multiple': 'Yes'} DVD,digital,Netflix {'multiple': 'Yes'} Online,VHS {'multiple': 'No'} Blu_Ray- 1
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8. 移动元素
一些数据被放置在错误的十年中。使用您所了解的有关 XML 的知识ElementTree来查找和修复十年数据错误。
打印出整个文档中的decade标签和标签会很有用
for decade in root.findall("./genre/decade"): print(decade.attrib) for year in decade.findall("./movie/year"): print(year.text, '\n')- 1
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输出：
{'years': '1980s'} 1981 1984 1985 {'years': '1990s'} 2000 1992 1992 {'years': '1970s'} 1979 {'years': '1980s'} 1986 2000 {'years': '1960s'} 1966 {'years': '2010s'} 2010 2011 {'years': '1980s'} 1984 {'years': '1990s'} 1991- 1
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错误十年的两年是2000年代的电影。使用 XPath 表达式找出这些电影是什么。
for movie in root.findall("./genre/decade/movie/[year='2000']"): print(movie.attrib)- 1
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输出：
{'favorite': 'False', 'title': 'X-Men'} {'favorite': 'FALSE', 'title': 'American Psycho'}- 1
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您必须在动作类型中添加一个新的十年标签，即 2000 年代，才能移动 X 战警数据。该
.SubElement()方法可用于将此标记添加到 XML 的末尾。action = root.find("./genre[@category='Action']") new_dec = ET.SubElement(action, 'decade') new_dec.attrib["years"] = '2000s' print(ET.tostring(action, encoding='utf8').decode('utf8'))- 1
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输出：
<?xml version='1.0' encoding='utf8'?> <genre category="Action"> <decade years="1980s"> <movie favorite="True" title="Indiana Jones: The raiders of the lost Ark"> <format multiple="No">DVD</format> <year>1981</year> <rating>PG</rating> <description> 'Archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before the Nazis.' </description> </movie> <movie favorite="True" title="THE KARATE KID"> <format multiple="Yes">DVD,Online</format> <year>1984</year> <rating>PG</rating> <description>None provided.</description> </movie> <movie favorite="False" title="Back to the Future"> <format multiple="No">Blu-ray</format> <year>1985</year> <rating>PG</rating> <description>Marty McFly</description> </movie> </decade> <decade years="1990s"> <movie favorite="False" title="X-Men"> <format multiple="Yes">dvd, digital</format> <year>2000</year> <rating>PG-13</rating> <description>Two mutants come to a private academy for their kind whose resident superhero team must oppose a terrorist organization with similar powers.</description> </movie> <movie favorite="True" title="Batman Returns"> <format multiple="No">VHS</format> <year>1992</year> <rating>PG13</rating> <description>NA.</description> </movie> <movie favorite="False" title="Reservoir Dogs"> <format multiple="No">Online</format> <year>1992</year> <rating>R</rating> <description>WhAtEvER I Want!!!?!</description> </movie> </decade> <decade years="2000s" /></genre>- 1
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.append()现在，分别使用和将X-Men电影附加到 2000 年代并将其从 1990 年代删除.remove()。xmen = root.find("./genre/decade/movie[@title='X-Men']") dec2000s = root.find("./genre[@category='Action']/decade[@years='2000s']") dec2000s.append(xmen) dec1990s = root.find("./genre[@category='Action']/decade[@years='1990s']") dec1990s.remove(xmen) print(ET.tostring(action, encoding='utf8').decode('utf8'))- 1
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输出：
<?xml version='1.0' encoding='utf8'?> <genre category="Action"> <decade years="1980s"> <movie favorite="True" title="Indiana Jones: The raiders of the lost Ark"> <format multiple="No">DVD</format> <year>1981</year> <rating>PG</rating> <description> 'Archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before the Nazis.' </description> </movie> <movie favorite="True" title="THE KARATE KID"> <format multiple="Yes">DVD,Online</format> <year>1984</year> <rating>PG</rating> <description>None provided.</description> </movie> <movie favorite="False" title="Back to the Future"> <format multiple="No">Blu-ray</format> <year>1985</year> <rating>PG</rating> <description>Marty McFly</description> </movie> </decade> <decade years="1990s"> <movie favorite="True" title="Batman Returns"> <format multiple="No">VHS</format> <year>1992</year> <rating>PG13</rating> <description>NA.</description> </movie> <movie favorite="False" title="Reservoir Dogs"> <format multiple="No">Online</format> <year>1992</year> <rating>R</rating> <description>WhAtEvER I Want!!!?!</description> </movie> </decade> <decade years="2000s"><movie favorite="False" title="X-Men"> <format multiple="Yes">dvd, digital</format> <year>2000</year> <rating>PG-13</rating> <description>Two mutants come to a private academy for their kind whose resident superhero team must oppose a terrorist organization with similar powers.</description> </movie> </decade></genre>- 1
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9. 构建 XML 文档
很好，所以你基本上可以将整部电影移到新的十年。将更改保存回 XML。
tree.write("movies.xml") tree = ET.parse('movies.xml') root = tree.getroot() print(ET.tostring(root, encoding='utf8').decode('utf8'))- 1
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输出：
<?xml version='1.0' encoding='utf8'?> <collection> <genre category="Action"> <decade years="1980s"> <movie favorite="True" title="Indiana Jones: The raiders of the lost Ark"> <format multiple="No">DVD</format> <year>1981</year> <rating>PG</rating> <description> 'Archaeologist and adventurer Indiana Jones is hired by the U.S. government to find the Ark of the Covenant before the Nazis.' </description> </movie> <movie favorite="True" title="THE KARATE KID"> <format multiple="Yes">DVD,Online</format> <year>1984</year> <rating>PG</rating> <description>None provided.</description> </movie> <movie favorite="False" title="Back to the Future"> <format multiple="No">Blu-ray</format> <year>1985</year> <rating>PG</rating> <description>Marty McFly</description> </movie> </decade> <decade years="1990s"> <movie favorite="True" title="Batman Returns"> <format multiple="No">VHS</format> <year>1992</year> <rating>PG13</rating> <description>NA.</description> </movie> <movie favorite="False" title="Reservoir Dogs"> <format multiple="No">Online</format> <year>1992</year> <rating>R</rating> <description>WhAtEvER I Want!!!?!</description> </movie> </decade> <decade years="2000s"><movie favorite="False" title="X-Men"> <format multiple="Yes">dvd, digital</format> <year>2000</year> <rating>PG-13</rating> <description>Two mutants come to a private academy for their kind whose resident superhero team must oppose a terrorist organization with similar powers.</description> </movie> </decade></genre> <genre category="Thriller"> <decade years="1970s"> <movie favorite="False" title="ALIEN"> <format multiple="No">DVD</format> <year>1979</year> <rating>R</rating> <description>"""""""""</description> </movie> </decade> <decade years="1980s"> <movie favorite="True" title="Ferris Bueller's Day Off"> <format multiple="No">DVD</format> <year>1986</year> <rating>PG13</rating> <description>Funny movie about a funny guy</description> </movie> <movie favorite="FALSE" title="American Psycho"> <format multiple="No">blue-ray</format> <year>2000</year> <rating>Unrated</rating> <description>psychopathic Bateman</description> </movie> </decade> </genre> <genre category="Comedy"> <decade years="1960s"> <movie favorite="False" title="Batman: The Movie"> <format multiple="Yes">DVD,VHS</format> <year>1966</year> <rating>PG</rating> <description>What a joke!</description> </movie> </decade> <decade years="2010s"> <movie favorite="True" title="Easy A"> <format multiple="No">DVD</format> <year>2010</year> <rating>PG--13</rating> <description>Emma Stone = Hester Prynne</description> </movie> <movie favorite="True" title="Dinner for SCHMUCKS"> <format multiple="Yes">DVD,digital,Netflix</format> <year>2011</year> <rating>Unrated</rating> <description>Tim (Rudd) is a rising executive who “succeeds” in finding the perfect guest, IRS employee Barry (Carell), for his boss’ monthly event, a so-called “dinner for idiots,” which offers certain advantages to the exec who shows up with the biggest buffoon. </description> </movie> </decade> <decade years="1980s"> <movie favorite="False" title="Ghostbusters"> <format multiple="Yes">Online,VHS</format> <year>1984</year> <rating>PG</rating> <description>Who ya gonna call?</description> </movie> </decade> <decade years="1990s"> <movie favorite="True" title="Robin Hood: Prince of Thieves"> <format multiple="No">Blu_Ray</format> <year>1991</year> <rating>Unknown</rating> <description>Robin Hood slaying</description> </movie> </decade> </genre> </collection>- 1
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10. 结论
关于 XML 和使用ElementTree.
标签构建树结构并指定应该在那里描述的值。使用智能结构可以轻松读取和写入 XML。标签总是需要左括号和右括号来显示父子关系。
属性进一步描述了如何验证标签或允许布尔指定。属性通常采用非常具体的值，以便 XML 解析器（和用户）可以使用这些属性来检查标记值。
ElementTree是一个重要的 Python 库，可让您解析和导航 XML 文档。使用ElementTree将 XML 文档分解为易于使用的树结构。如有疑问，请将其打印出来 ( print(ET.tostring(root, encoding=‘utf8’).decode(‘utf8’))) - 使用这个有用的打印语句一次查看整个 XML 文档。它有助于检查何时从 XML 中编辑、添加或删除。
参考：
- XML 文档具有称为元素的部分，由开始和结束标记定义。标签是一种以 开头
-
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- 原文地址：https://blog.csdn.net/xixihahalelehehe/article/details/126242593
