simple, elegant HTML, XHTML and XML generation
Simple, elegant HTML, XHTML and XML generation.
Constructing your HTML
To construct HTML start with an instance of html.HTML(). Add tags by accessing the tag’s attribute on that object. For example:
>>> from html import HTML >>> h = HTML() >>> h.p('Hello, world!') >>> print h # or print(h) in python 3+ <p>Hello, world!</p>
You may supply a tag name and some text contents when creating a HTML instance:
>>> h = HTML('html', 'text') >>> print h <html>text</html>
You may also append text content later using the tag’s .text() method or using augmented addition +=. Any HTML-specific characters (<>&") in the text will be escaped for HTML safety as appropriate unless escape=False is passed. Each of the following examples uses a new HTML instance:
>>> p = h.p('hello world!\n') >>> p.br >>> p.text('more → text', escape=False) >>> p += ' ... augmented' >>> h.p >>> print h <p>hello, world!<br>more → text ... augmented</p> <p>
Note also that the top-level HTML object adds newlines between tags by default. Finally in the above you’ll see an empty paragraph tag - tags with no contents get no closing tag.
If the tag should have sub-tags you have two options. You may either add the sub-tags directly on the tag:
>>> l = h.ol >>> l.li('item 1') >>> l.li.b('item 2 > 1') >>> print h <ol> <li>item 1</li> <li><b>item 2 > 1</b></li> </ol>
Note that the default behavior with lists (and tables) is to add newlines between sub-tags to generate a nicer output. You can also see in that example the chaining of tags in l.li.b.
Tag attributes may be passed in as well:
>>> t = h.table(border='1') >>> for i in range(2): >>> r = t.tr >>> r.td('column 1') >>> r.td('column 2') >>> print t <table border="1"> <tr><td>column 1</td><td>column 2</td></tr> <tr><td>column 1</td><td>column 2</td></tr> </table>
A variation on the above is to use a tag as a context variable. The following is functionally identical to the first list construction but with a slightly different sytax emphasising the HTML structure:
>>> with h.ol as l: ... l.li('item 1') ... l.li.b('item 2 > 1')
You may turn off/on adding newlines by passing newlines=False or True to the tag (or HTML instance) at creation time:
>>> l = h.ol(newlines=False) >>> l.li('item 1') >>> l.li('item 2') >>> print h <ol><li>item 1</li><li>item 2</li></ol>
Since we can’t use class as a keyword, the library recognises klass as a substitute:
>>> print h.p(content, klass="styled") <p class="styled">content</p>
HTML will work with either regular strings or unicode strings, but not both at the same time.
Obtain the final unicode string by calling unicode() on the HTML instance:
>>> h = HTML() >>> h.p(u'Some Euro: €1.14') >>> unicode(h) u'<p>Some Euro: €1.14</p>'
If (under Python 2.x) you add non-unicode strings or attempt to get the resultant HTML source through any means other than unicode() then you will most likely get one of the following errors raised:
- Probably means you’ve added non-unicode strings to your HTML.
- Probably means you’re trying to get the resultant HTML using print or str() (or %s).
How generation works
The HTML document is generated when the HTML instance is “stringified”. This could be done either by invoking str() on it, or just printing it. It may also be returned directly as the “iterable content” from a WSGI app function.
You may also render any tag or sub-tag at any time by stringifying it.
Tags with no contents (either text or sub-tags) will have no closing tag. There is no “special list” of tags that must always have closing tags, so if you need to force a closing tag you’ll need to provide some content, even if it’s just a single space character.
Rendering doesn’t affect the HTML document’s state, so you can add to or otherwise manipulate the HTML after you’ve stringified it.
To construct XHTML start with an instance of html.XHTML() and use it as you would an HTML instance. Empty elements will now be rendered with the appropriate XHTML minimized tag syntax. For example:
>>> from html import XHTML >>> h = XHTML() >>> h.p >>> h.br >>> print h <p></p> <br />
A slight tweak to the html.XHTML() implementation allows us to generate arbitrary XML using html.XML():
>>> from html import XML >>> h = XML('xml') >>> h.p >>> h.br('hi there') >>> print h <xml> <p /> <br>hi there</br> </xml>
Version History (in Brief)
- 1.16 detect and raise a more useful error when some WSGI frameworks attempt to call HTML.read(). Also added ability to add new content using the += operator.
- 1.15 fix Python 3 compatibility (unit tests)
- 1.14 added plain XML support
- 1.13 allow adding (X)HTML instances (tags) as new document content
- 1.12 fix handling of XHTML empty tags when generating unicode output (thanks Carsten Eggers)
- 1.11 remove setuptools dependency
- 1.10 support plain ol’ distutils again
- 1.9 added unicode support for Python 2.x
- 1.8 added Python 3 compatibility
- 1.7 added Python 2.5 compatibility and escape argument to tag construction
- 1.6 added .raw_text() and and WSGI compatibility
- 1.5 added XHTML support
- 1.3 added more documentation, more tests
- 1.2 added special-case klass / class attribute
- 1.1 added escaping control
- 1.0 was the initial release
I would be interested to know whether this module is useful - if you use it please indicate so at https://www.ohloh.net/p/pyhtml
This code is copyright 2009-2011 eKit.com Inc (http://www.ekit.com/) See the end of the source file for the license of use. XHTML support was contributed by Michael Haubenwallner.