diff options
Diffstat (limited to 'python/pystache/README.md')
| -rw-r--r-- | python/pystache/README.md | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/python/pystache/README.md b/python/pystache/README.md new file mode 100644 index 0000000000..54a96088b4 --- /dev/null +++ b/python/pystache/README.md @@ -0,0 +1,276 @@ +Pystache +======== + +<!-- Since PyPI rejects reST long descriptions that contain HTML, --> +<!-- HTML comments must be removed when converting this file to reST. --> +<!-- For more information on PyPI's behavior in this regard, see: --> +<!-- http://docs.python.org/distutils/uploading.html#pypi-package-display --> +<!-- The Pystache setup script strips 1-line HTML comments prior --> +<!-- to converting to reST, so all HTML comments should be one line. --> +<!-- --> +<!-- We leave the leading brackets empty here. Otherwise, unwanted --> +<!-- caption text shows up in the reST version converted by pandoc. --> + + + + +[Pystache](http://defunkt.github.com/pystache) is a Python +implementation of [Mustache](http://mustache.github.com/). Mustache is a +framework-agnostic, logic-free templating system inspired by +[ctemplate](http://code.google.com/p/google-ctemplate/) and +[et](http://www.ivan.fomichev.name/2008/05/erlang-template-engine-prototype.html). +Like ctemplate, Mustache "emphasizes separating logic from presentation: +it is impossible to embed application logic in this template language." + +The [mustache(5)](http://mustache.github.com/mustache.5.html) man page +provides a good introduction to Mustache's syntax. For a more complete +(and more current) description of Mustache's behavior, see the official +[Mustache spec](https://github.com/mustache/spec). + +Pystache is [semantically versioned](http://semver.org) and can be found +on [PyPI](http://pypi.python.org/pypi/pystache). This version of +Pystache passes all tests in [version +1.1.2](https://github.com/mustache/spec/tree/v1.1.2) of the spec. + + +Requirements +------------ + +Pystache is tested with-- + +- Python 2.4 (requires simplejson [version + 2.0.9](http://pypi.python.org/pypi/simplejson/2.0.9) or earlier) +- Python 2.5 (requires + [simplejson](http://pypi.python.org/pypi/simplejson/)) +- Python 2.6 +- Python 2.7 +- Python 3.1 +- Python 3.2 +- Python 3.3 +- [PyPy](http://pypy.org/) + +[Distribute](http://packages.python.org/distribute/) (the setuptools fork) +is recommended over [setuptools](http://pypi.python.org/pypi/setuptools), +and is required in some cases (e.g. for Python 3 support). +If you use [pip](http://www.pip-installer.org/), you probably already satisfy +this requirement. + +JSON support is needed only for the command-line interface and to run +the spec tests. We require simplejson for earlier versions of Python +since Python's [json](http://docs.python.org/library/json.html) module +was added in Python 2.6. + +For Python 2.4 we require an earlier version of simplejson since +simplejson stopped officially supporting Python 2.4 in simplejson +version 2.1.0. Earlier versions of simplejson can be installed manually, +as follows: + + pip install 'simplejson<2.1.0' + +Official support for Python 2.4 will end with Pystache version 0.6.0. + +Install It +---------- + + pip install pystache + +And test it-- + + pystache-test + +To install and test from source (e.g. from GitHub), see the Develop +section. + +Use It +------ + + >>> import pystache + >>> print pystache.render('Hi {{person}}!', {'person': 'Mom'}) + Hi Mom! + +You can also create dedicated view classes to hold your view logic. + +Here's your view class (in .../examples/readme.py): + + class SayHello(object): + def to(self): + return "Pizza" + +Instantiating like so: + + >>> from pystache.tests.examples.readme import SayHello + >>> hello = SayHello() + +Then your template, say\_hello.mustache (by default in the same +directory as your class definition): + + Hello, {{to}}! + +Pull it together: + + >>> renderer = pystache.Renderer() + >>> print renderer.render(hello) + Hello, Pizza! + +For greater control over rendering (e.g. to specify a custom template +directory), use the `Renderer` class like above. One can pass attributes +to the Renderer class constructor or set them on a Renderer instance. To +customize template loading on a per-view basis, subclass `TemplateSpec`. +See the docstrings of the +[Renderer](https://github.com/defunkt/pystache/blob/master/pystache/renderer.py) +class and +[TemplateSpec](https://github.com/defunkt/pystache/blob/master/pystache/template_spec.py) +class for more information. + +You can also pre-parse a template: + + >>> parsed = pystache.parse(u"Hey {{#who}}{{.}}!{{/who}}") + >>> print parsed + [u'Hey ', _SectionNode(key=u'who', index_begin=12, index_end=18, parsed=[_EscapeNode(key=u'.'), u'!'])] + +And then: + + >>> print renderer.render(parsed, {'who': 'Pops'}) + Hey Pops! + >>> print renderer.render(parsed, {'who': 'you'}) + Hey you! + +Python 3 +-------- + +Pystache has supported Python 3 since version 0.5.1. Pystache behaves +slightly differently between Python 2 and 3, as follows: + +- In Python 2, the default html-escape function `cgi.escape()` does + not escape single quotes. In Python 3, the default escape function + `html.escape()` does escape single quotes. +- In both Python 2 and 3, the string and file encodings default to + `sys.getdefaultencoding()`. However, this function can return + different values under Python 2 and 3, even when run from the same + system. Check your own system for the behavior on your system, or do + not rely on the defaults by passing in the encodings explicitly + (e.g. to the `Renderer` class). + +Unicode +------- + +This section describes how Pystache handles unicode, strings, and +encodings. + +Internally, Pystache uses [only unicode +strings](http://docs.python.org/howto/unicode.html#tips-for-writing-unicode-aware-programs) +(`str` in Python 3 and `unicode` in Python 2). For input, Pystache +accepts both unicode strings and byte strings (`bytes` in Python 3 and +`str` in Python 2). For output, Pystache's template rendering methods +return only unicode. + +Pystache's `Renderer` class supports a number of attributes to control +how Pystache converts byte strings to unicode on input. These include +the `file_encoding`, `string_encoding`, and `decode_errors` attributes. + +The `file_encoding` attribute is the encoding the renderer uses to +convert to unicode any files read from the file system. Similarly, +`string_encoding` is the encoding the renderer uses to convert any other +byte strings encountered during the rendering process into unicode (e.g. +context values that are encoded byte strings). + +The `decode_errors` attribute is what the renderer passes as the +`errors` argument to Python's built-in unicode-decoding function +(`str()` in Python 3 and `unicode()` in Python 2). The valid values for +this argument are `strict`, `ignore`, and `replace`. + +Each of these attributes can be set via the `Renderer` class's +constructor using a keyword argument of the same name. See the Renderer +class's docstrings for further details. In addition, the `file_encoding` +attribute can be controlled on a per-view basis by subclassing the +`TemplateSpec` class. When not specified explicitly, these attributes +default to values set in Pystache's `defaults` module. + +Develop +------- + +To test from a source distribution (without installing)-- + + python test_pystache.py + +To test Pystache with multiple versions of Python (with a single +command!), you can use [tox](http://pypi.python.org/pypi/tox): + + pip install 'virtualenv<1.8' # Version 1.8 dropped support for Python 2.4. + pip install 'tox<1.4' # Version 1.4 dropped support for Python 2.4. + tox + +If you do not have all Python versions listed in `tox.ini`-- + + tox -e py26,py32 # for example + +The source distribution tests also include doctests and tests from the +Mustache spec. To include tests from the Mustache spec in your test +runs: + + git submodule init + git submodule update + +The test harness parses the spec's (more human-readable) yaml files if +[PyYAML](http://pypi.python.org/pypi/PyYAML) is present. Otherwise, it +parses the json files. To install PyYAML-- + + pip install pyyaml + +To run a subset of the tests, you can use +[nose](http://somethingaboutorange.com/mrl/projects/nose/0.11.1/testing.html): + + pip install nose + nosetests --tests pystache/tests/test_context.py:GetValueTests.test_dictionary__key_present + +### Using Python 3 with Pystache from source + +Pystache is written in Python 2 and must be converted to Python 3 prior to +using it with Python 3. The installation process (and tox) do this +automatically. + +To convert the code to Python 3 manually (while using Python 3)-- + + python setup.py build + +This writes the converted code to a subdirectory called `build`. +By design, Python 3 builds +[cannot](https://bitbucket.org/tarek/distribute/issue/292/allow-use_2to3-with-python-2) +be created from Python 2. + +To convert the code without using setup.py, you can use +[2to3](http://docs.python.org/library/2to3.html) as follows (two steps)-- + + 2to3 --write --nobackups --no-diffs --doctests_only pystache + 2to3 --write --nobackups --no-diffs pystache + +This converts the code (and doctests) in place. + +To `import pystache` from a source distribution while using Python 3, be +sure that you are importing from a directory containing a converted +version of the code (e.g. from the `build` directory after converting), +and not from the original (unconverted) source directory. Otherwise, you will +get a syntax error. You can help prevent this by not running the Python +IDE from the project directory when importing Pystache while using Python 3. + + +Mailing List +------------ + +There is a [mailing list](http://librelist.com/browser/pystache/). Note +that there is a bit of a delay between posting a message and seeing it +appear in the mailing list archive. + +Credits +------- + + >>> context = { 'author': 'Chris Wanstrath', 'maintainer': 'Chris Jerdonek' } + >>> print pystache.render("Author: {{author}}\nMaintainer: {{maintainer}}", context) + Author: Chris Wanstrath + Maintainer: Chris Jerdonek + +Pystache logo by [David Phillips](http://davidphillips.us/) is licensed +under a [Creative Commons Attribution-ShareAlike 3.0 Unported +License](http://creativecommons.org/licenses/by-sa/3.0/deed.en_US). + |