ANN: EmPy 3.1 -- A powerful templating system for Python

Erik Max Francis
Mon, 08 Sep 2003 19:18:49 -0700


    A powerful and robust templating system for Python.


    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.  Context name and line
    number changes can be done with '@?' and '@!' respectively.
    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 3.1.

    The latest version of the software is available in a tarball here:

    The official URL for this Web site is


    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 (using Java runtimes 1.3 and 1.4).  The
    included test script is intended to run on Unix-like systems with
    a Bourne shell.


    This code is released under the GPL.


Release history [since 3.0.4]

    - 3.1; 2003 Aug 8.  Unicode support (Python 2.0 and above); added
      Document and Processor helper classes for processing
      significators; added --no-prefix option for suppressing all

   Erik Max Francis && &&
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