<HTML><HEAD><TITLE>Creating true standalone applications in Python</TITLE></HEAD>
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<H1>Creating true standalone applications in Python</H1>
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<EM>NOTE</EM> This document is obsolete. See <A HREF="freezing.html">Freezing Python
scripts</A> for a more up-to-date treatise. <p>
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You can use Python to create true standalone macintosh applications: applications
that you can distribute to other people as a single file, without dependencies
on Python being installed, etc. The process is not easy, however, and at the
moment you need a source distribution (and a C development environment, CodeWarrior
most preferred). You should first familiarize yourself with the sections
<a href="building.html">building Python from source</a> and
<a href="example2.html">building applets</a>. <p>

The application we are going to build will contain a complete interpreter,
plus <code>'PYC '</code> resources for all the Python modules the program uses.
We start by creating a resource file that contains all the modules we need,
in PYC-resource form. There are two ways to do this:
<UL>
<LI> Modify the standard <code>freeze.py</code> module to print the names of
all modules used. Copy these to a single folder, run <code>compileall.py</code>
on that folder and then run <code>PackLibDir.py</code> from the scripts folder
to create the resourcefile. This has one disadvantage: freeze finds the modules
used by parsing your Python code, so modules you don't use (for instance because
they are system-dependent and not used on the mac) are also included. You
may also have problems with dynamically loaded modules. You will also have to rename
your main module to __main__.py.

<LI> Another way to find the modules used is by option-starting your script
and setting the "interactive mode after script" flag. Exercise every corner of
your program so all your modules have been imported, and when you exit your
program and get back to the interpreter use <code>findmodulefiles.findmodulefiles</code>
to get a list of all modules used. You can now use
<code>findmodulefiles.mkpycresourcefile</code> to create your resourcefile.
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Next we create the application project. Copy the <code>PythonStandalone.prj</code>
project, replace <code>macapplication.c</code> by <code>macapplet.c</code> and
replace <code>bundle.rsrc</code> by <code>appletbundle.rsrc</code>. Also
add the PYC resource file you made in the previous step and any other resource
files you need. Set the target output file names (for all three of ppc/68k/fat).
Build your application. <p>

Finally we have to give the application the right <code>sys.path</code> initialisation.
We do this by dropping the application on <code>EditPythonPrefs</code> and removing
all path components replacing them with a single <code>$(APPLICATION)</code>. You
may have to use ResEdit after this step to remove an "alis" resource from your application,
I am not sure why this is sometimes created. <p>

If you want to get fancy you may be able to make your application smaller by removing
all unused builtin modules. If you used the findmodulefiles method above to find
your modules you can start a standalone interpreter and use
<code>findmodulefiles.findunusedbuiltins</code> to get the names of all builtin
modules your program doesn't use. You can then create a private copy of
<code>config.c</code> from which you remove all unused modules.

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