pep-0206.txt

PEP: 206
Title: 2.0 Batteries Included
Version: $Revision$
Author: moshez@math.huji.ac.il (Moshe Zadka)
Python-Version: 2.0
Status: Draft


Introduction

    This PEP describes the `batteries included' proposal for Python
    2.0, the fat distribution containing commonly used third party
    extension modules.  This PEP tracks the status and ownership of
    this proposal, slated for introduction in Python 2.0.  It contains
    a description of the proposal and outlines how to support it.


Batteries Included Philosophy

    The Python source distribution always maintained the philosophy of
    "batteries included" -- having a rich and versatile standard
    library which is immediately available, without making the user
    download separate packages.  This gives the Python language a head
    start in many projects.  However, the Python standard library
    often relies on important Open Source libraries which might be
    unavailable on many computers, so that the user has to separately
    download and compile those.  Some examples are the zlib
    compression library, and the gmp number manipulation library.

    The original coinage of the term "batteries included" can be found
    here:

    http://www.uk.research.att.com/~fms/ipc7/tr-1998-9.html


The Proposed Solution

    The proposed solution is to maintain an alternate form of distribution,
    nicknamed the "sumo" interpreter. It will be structured as a core 
    interpreter + extra useful libraries. In addition, the build procedure 
    will be changed to build those libraries by default, and build the Python 
    modules which rely on them linked against those libraries.  Individual 
    users will still be able to link the Python modules against already
    installed libraries, or disable them completely.

    Additionally, some Open Source third-party Python modules will
    also be distributed in the "sumo" distribution.  The
    difference between those and external libraries is that the former
    are distributed in order to make the Python distribution self
    contained, and the latter are added so there will be new
    functionality in out-of-the-box Python.

Python Advanced Library

    Since it is decided that the additions to the interpreter will live
    in a seperate directory, they can even be distributed seperately, 
    as an additional library. This is called the "Python Advanced Library",
    or PAL. This will also solve the problem of an advanced library module 
    failing -- the core interpreter will still be built, tested and installed.
    Since the compilation of the other modules be helped by Python scripts,
    it is quite possible that it will even install as many modules as it
    can.

Suggested Libraries and Modules

    Here is the tentative list of libraries which are proposed to be
    dealt with in this manner, and where they can be downloaded:

    zlib -- http://www.info-zip.org/pub/infozip/zlib/zlib.tar.gz
    expat -- ftp://ftp.jclark.com/pub/xml/expat.zip
    Tcl -- http://dev.scriptics.com:80/download/tcl/tcl8_3/tcl8.3.1.tar.gz
    Tk -- http://dev.scriptics.com:80/download/tcl/tcl8_3/tk8.3.1.tar.gz
    PIL -- http://www.pythonware.com/downloads/Imaging-1.1.tar.gz
    libjpeg -- ftp://ftp.uu.net/graphics/jpeg/jpegsrc.v6b.tar.gz
    ncurses -- ftp://dickey.his.com/ncurses/ncurses.tar.gz

    TBD, the following:

    NumPy -- http://download.sourceforge.net/numpy/Numerical-15.3.tgz
    Pmw --  ftp://ftp.dscpl.com.au/pub/pmw/Pmw.0.8.4.tar.gz
    BLT -- ftp://ftp.tcltk.com/aa004735/pub/blt/BLT2.4u.tar.gz
    piddle -- http://download.sourceforge.net/piddle/piddle-1.0b7.tgz


Connection to Distutils

    Since Python 2.0 comes with a new mechanism of distributing Python 
    modules, called ``distutils'', we should be able to use it. Specificially,
    since distutils has the capability or building Python modules in an
    automatic fashion, it is hoped that some of the work will consist in
    creating a new directory with the source, and having the ``super-make''
    run "./setup --install" in those directories. This should at least take
    care of PIL, NumPy and Pmw. In addition, it is hoped that this mechanism
    will be easy enough to add other Python modules as user requests direct
    us.
    


Software covered by the GNU Public License

    While many Python modules rely on software distributed under the
    GNU General Public License and the GNU Lesser General Public
    License, no such sources are proposed here to be added to the
    sumo interpreter.  Currently, the Python interpreter is
    distributed under a closed-source-friendly license, which means
    that it is possible to include it in a closed source product.
    Making redistributers worry about which parts they need to remove
    to make closed-source redistribution legal might cost more then
    the benefits.


Open Issues

    Where does all this source live? 

    What should the build procedure look like?

    How are the additional modules tested?

    ESR also mentioned libpng, but I don't know of a Python module
    that uses it.


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