ANN: EmPy 3.0 -- Python templating system
Erik Max Francis
max@alcyone.com
Sun, 08 Jun 2003 19:52:04 -0700
Summary
A templating system for Python.
Overview
EmPy is a system for embedding Python expressions and statements
in template text; it takes an EmPy source file, processes it, and
produces output. This is accomplished via expansions, which are
special signals to the EmPy system and are set off by a special
prefix (by default the at sign, '@'). EmPy can expand arbitrary
Python expressions and statements in this way, as well as a
variety of special forms. Textual data not explicitly delimited
in this way is sent unaffected to the output, allowing Python to
be used in effect as a markup language. Also supported are
callbacks via hooks, recording and playback via diversions, and
dynamic, chainable filters. The system is highly configurable via
command line options and embedded commands.
Expressions are embedded in text with the '@(...)' notation;
variations include conditional expressions with '@(...?...!...)'
and the ability to handle thrown exceptions with '@(...$...)'. As
a shortcut, simple variables and expressions can be abbreviated as
'@variable', '@object.attribute', '@function(arguments)',
'@sequence[index]', and combinations. Full-fledged statements
are embedded with '@{...}'. Control flow in terms of conditional
or repeated expansion is available with '@[...]'. A '@' followed
by a whitespace character (including a newline) expands to
nothing, allowing string concatenations and line continuations.
Comments are indicated with '@#' and consume the rest of the line,
up to and including the trailing newline. '@%' indicate
"significators," which are special forms of variable assignment
intended to specify per-file identification information in a
format which is easy to parse externally. Escape sequences
analogous to those in C can be specified with '@\...', and finally
a '@@' sequence expands to a single literal at sign.
Getting the software
The current version of empy is 3.0.
The latest version of the software is available in a tarball here:
http://www.alcyone.com/pyos/empy/empy-latest.tar.gz.
The official URL for this Web site is
http://www.alcyone.com/pyos/empy/.
Requirements
EmPy should work with any version of Python from 1.5.2 onward. It
has been tested with all major versions of CPython from 1.5 up,
and Jython from 2.0 up. The included test script is intended to
run on UNIX-like systems with a Bourne shell.
License
This code is released under the GPL.
....
Release history [since 2.3]
- 3.0; 2003 Jun 1. Control markups with '@[...]'; remove
substitutions (use control markups instead); support
'@(...?...!...)' for conditional expressions in addition to the
now-deprecated '@(...?...:...)' variety; add acknowledgements
and glossary sections to documentation; rename buffering option
back to -b; add -m option and 'EMPY_PSEUDO' environment variable
for changing the pseudomodule name; add -n option and
'EMPY_NO_OVERRIDE' environment variable for suppressing
'sys.stdout' proxy; rename main error class to 'Error'; add
standalone 'expand' function; add --binary and --chunk-size
options; reengineer parsing system to use Tokens for easy
extensibility; safeguard curly braces in simple expressions
(meaningless in Python and thus likely a typographical error) by
making them a parse error; fix bug involving custom Interpreter
instances ignoring globals argument; distutils support.
--
Erik Max Francis && max@alcyone.com && http://www.alcyone.com/max/
__ San Jose, CA, USA && 37 20 N 121 53 W && &tSftDotIotE
/ \ What a crime to waste [youth] on children.
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