`lxml.builder.E`

来自http://lxml.de/tutorial.html#the-e-factory的示例：

>>> from lxml.builder import E

>>> def CLASS(*args): # class is a reserved word in Python
...     return {"class":' '.join(args)}

>>> html = page = (
...   E.html(       # create an Element called "html"
...     E.head(
...       E.title("This is a sample document")
...     ),
...     E.body(
...       E.h1("Hello!", CLASS("title")),
...       E.p("This is a paragraph with ", E.b("bold"), " text in it!"),
...       E.p("This is another paragraph, with a", "\n      ",
...         E.a("link", href="http://www.python.org"), "."),
...       E.p("Here are some reserved characters: <spam&egg>."),
...       etree.XML("<p>And finally an embedded XHTML fragment.</p>"),
...     )
...   )
... )

`lxml.html.builder`

来自http://lxml.de/lxmlhtml.html#creating-html-with-the-e-factory的示例：

>>> from lxml.html import builder as E
>>> from lxml.html import usedoctest
>>> html = E.HTML(
...   E.HEAD(
...     E.LINK(rel="stylesheet", href="great.css", type="text/css"),
...     E.TITLE("Best Page Ever")
...   ),
...   E.BODY(
...     E.H1(E.CLASS("heading"), "Top News"),
...     E.P("World News only on this page", style="font-size: 200%"),
...     "Ah, and here's some more text, by the way.",
...     lxml.html.fromstring("<p>... and this is a parsed fragment ...</p>")
...   )
... )

Answer 1

Python库lxml似乎提供了几个用于生成HTML文档的构建器。它们之间的区别是什么？

lxml.builder.E正在使用工厂模式

 from lxml.html import builder as E
 from lxml.html import usedoctest
 html = E.HTML(
   E.HEAD(
     E.LINK(rel="stylesheet", href="great.css", type="text/css"),
     E.TITLE("Best Page Ever")
   ),
   E.BODY(
     E.H1(E.CLASS("heading"), "Top News"),
     E.P("World News only on this page", style="font-size: 200%"),
     "Ah, and here's some more text, by the way.",
     lxml.html.fromstring("... and this is a parsed fragment ...")
   )

lxml.builder正在使用原型模式：

 from lxml.builder import E

 def CLASS(*args): # class is a reserved word in Python
     return {"class":' '.join(args)}

 html = page = (
   E.html(       # create an Element called "html"
     E.head(
       E.title("This is a sample document")
     ),
     E.body(
       E.h1("Hello!", CLASS("title")),
       E.p("This is a paragraph with ", E.b("bold"), " text in it!"),
       E.p("This is another paragraph, with a", "\n      ",
         E.a("link", href="http://www.python.org"), "."),
       E.p("Here are some reserved characters: ."),
       etree.XML("And finally an embedded XHTML fragment."),
     )
   )
 )

虽然我可以手动添加xmlns声明，但这不太优雅。

XSLT将是另一种选择。

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns="http://www.w3.org/1999/xhtml">
<xsl:output method="xml" encoding="utf-8" version="" indent="yes" standalone="no" media-type="text/html" omit-xml-declaration="no" doctype-system="about:legacy-compat" />
<xsl:template match="/">
  <html xmlns="http://www.w3.org/1999/xhtml">
    <xsl:copy-of select="."/>
  </html>
</xsl:template>
</xsl:stylesheet>

<强>参考

Answer 2

从lxml.builder中混合ElementMaker和E对我来说很有用：

from lxml import etree
from lxml.builder import ElementMaker,E

M=ElementMaker(namespace=None,
               nsmap={None: "http://www.w3.org/1999/xhtml"})
html = M.html(E.head(E.title("Test page")),
              E.body(E.p("Hello world")))
result = etree.tostring(html,
                        xml_declaration=True,
                        doctype='<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">',
                        encoding='utf-8',
                        standalone=False,
                        with_tail=False,
                        method='xml',
                        pretty_print=True)
print result

结果是

<?xml version='1.0' encoding='utf-8' standalone='no'?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>Test page</title>
  </head>
  <body>
    <p>Hello world</p>
  </body>
</html>

Answer 3

Python库lxml似乎为生成HTML文档。这些有什么区别？

lxml.builder.E提供了一个带有类<class 'lxml.etree._Element'>的XML文档，这意味着该对象不了解（而且可能不是）蜂拥html文档。

lxml.html.builder提供一个<class 'lxml.html.HtmlElement'>，这意味着您有一个知道它是html的对象，并提供了{e.body或e.make_links_absolute()这样的HTML专用方法和属性。 3}}

推荐使用lxml生成XHTML文档的方法

`lxml.builder.E`

`lxml.html.builder`

3 个答案: