gecko-dev/python/pystache/setup_description.rst

.. Do not edit this file.  This file is auto-generated for PyPI by setup.py
.. using pandoc, so edits should go in the source files rather than here.

Pystache
========

.. figure:: http://defunkt.github.com/pystache/images/logo_phillips.png
   :alt: mustachioed, monocled snake by David Phillips

.. figure:: https://secure.travis-ci.org/defunkt/pystache.png
   :alt: Travis CI current build status

`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>`__.
|image0|

History
=======

**Note:** Official support for Python 2.4 will end with Pystache version
0.6.0.

0.5.4 (2014-07-11)
------------------

-  Bugfix: made test with filenames OS agnostic (issue #162).

0.5.3 (2012-11-03)
------------------

-  Added ability to customize string coercion (e.g. to have None render
   as ``''``) (issue #130).
-  Added Renderer.render\_name() to render a template by name (issue
   #122).
-  Added TemplateSpec.template\_path to specify an absolute path to a
   template (issue #41).
-  Added option of raising errors on missing tags/partials:
   ``Renderer(missing_tags='strict')`` (issue #110).
-  Added support for finding and loading templates by file name in
   addition to by template name (issue #127). [xgecko]
-  Added a ``parse()`` function that yields a printable, pre-compiled
   parse tree.
-  Added support for rendering pre-compiled templates.
-  Added Python 3.3 to the list of supported versions.
-  Added support for `PyPy <http://pypy.org/>`__ (issue #125).
-  Added support for `Travis CI <http://travis-ci.org>`__ (issue #124).
   [msabramo]
-  Bugfix: ``defaults.DELIMITERS`` can now be changed at runtime (issue
   #135). [bennoleslie]
-  Bugfix: exceptions raised from a property are no longer swallowed
   when getting a key from a context stack (issue #110).
-  Bugfix: lambda section values can now return non-ascii, non-unicode
   strings (issue #118).
-  Bugfix: allow ``test_pystache.py`` and ``tox`` to pass when run from
   a downloaded sdist (i.e. without the spec test directory).
-  Convert HISTORY and README files from reST to Markdown.
-  More robust handling of byte strings in Python 3.
-  Added Creative Commons license for David Phillips's logo.

0.5.2 (2012-05-03)
------------------

-  Added support for dot notation and version 1.1.2 of the spec (issue
   #99). [rbp]
-  Missing partials now render as empty string per latest version of
   spec (issue #115).
-  Bugfix: falsey values now coerced to strings using str().
-  Bugfix: lambda return values for sections no longer pushed onto
   context stack (issue #113).
-  Bugfix: lists of lambdas for sections were not rendered (issue #114).

0.5.1 (2012-04-24)
------------------

-  Added support for Python 3.1 and 3.2.
-  Added tox support to test multiple Python versions.
-  Added test script entry point: pystache-test.
-  Added \_\_version\_\_ package attribute.
-  Test harness now supports both YAML and JSON forms of Mustache spec.
-  Test harness no longer requires nose.

0.5.0 (2012-04-03)
------------------

This version represents a major rewrite and refactoring of the code base
that also adds features and fixes many bugs. All functionality and
nearly all unit tests have been preserved. However, some backwards
incompatible changes to the API have been made.

Below is a selection of some of the changes (not exhaustive).

Highlights:

-  Pystache now passes all tests in version 1.0.3 of the `Mustache
   spec <https://github.com/mustache/spec>`__. [pvande]
-  Removed View class: it is no longer necessary to subclass from View
   or from any other class to create a view.
-  Replaced Template with Renderer class: template rendering behavior
   can be modified via the Renderer constructor or by setting attributes
   on a Renderer instance.
-  Added TemplateSpec class: template rendering can be specified on a
   per-view basis by subclassing from TemplateSpec.
-  Introduced separation of concerns and removed circular dependencies
   (e.g. between Template and View classes, cf. `issue
   #13 <https://github.com/defunkt/pystache/issues/13>`__).
-  Unicode now used consistently throughout the rendering process.
-  Expanded test coverage: nosetests now runs doctests and ~105 test
   cases from the Mustache spec (increasing the number of tests from 56
   to ~315).
-  Added a rudimentary benchmarking script to gauge performance while
   refactoring.
-  Extensive documentation added (e.g. docstrings).

Other changes:

-  Added a command-line interface. [vrde]
-  The main rendering class now accepts a custom partial loader (e.g. a
   dictionary) and a custom escape function.
-  Non-ascii characters in str strings are now supported while
   rendering.
-  Added string encoding, file encoding, and errors options for decoding
   to unicode.
-  Removed the output encoding option.
-  Removed the use of markupsafe.

Bug fixes:

-  Context values no longer processed as template strings.
   [jakearchibald]
-  Whitespace surrounding sections is no longer altered, per the spec.
   [heliodor]
-  Zeroes now render correctly when using PyPy. [alex]
-  Multline comments now permitted. [fczuardi]
-  Extensionless template files are now supported.
-  Passing ``**kwargs`` to ``Template()`` no longer modifies the
   context.
-  Passing ``**kwargs`` to ``Template()`` with no context no longer
   raises an exception.

0.4.1 (2012-03-25)
------------------

-  Added support for Python 2.4. [wangtz, jvantuyl]

0.4.0 (2011-01-12)
------------------

-  Add support for nested contexts (within template and view)
-  Add support for inverted lists
-  Decoupled template loading

0.3.1 (2010-05-07)
------------------

-  Fix package

0.3.0 (2010-05-03)
------------------

-  View.template\_path can now hold a list of path
-  Add {{& blah}} as an alias for {{{ blah }}}
-  Higher Order Sections
-  Inverted sections

0.2.0 (2010-02-15)
------------------

-  Bugfix: Methods returning False or None are not rendered
-  Bugfix: Don't render an empty string when a tag's value is 0.
   [enaeseth]
-  Add support for using non-callables as View attributes.
   [joshthecoder]
-  Allow using View instances as attributes. [joshthecoder]
-  Support for Unicode and non-ASCII-encoded bytestring output.
   [enaeseth]
-  Template file encoding awareness. [enaeseth]

0.1.1 (2009-11-13)
------------------

-  Ensure we're dealing with strings, always
-  Tests can be run by executing the test file directly

0.1.0 (2009-11-12)
------------------

-  First release

License
=======

Copyright (C) 2012 Chris Jerdonek. All rights reserved.

Copyright (c) 2009 Chris Wanstrath

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

.. |image0| image:: http://i.creativecommons.org/l/by-sa/3.0/88x31.png