Mod by Donovan Preston to allow MacPython to live in a Python.app bundle and understand the __main__.py convention used there for applets. This gives us applets that work on both OS9 and OSX! (Although "applet" may not be the correct word for something that is going to be multimegabyte:-).

But: the code is currently disabled, as it requires CodeWarrior 7 and I'm still using 6.
diff --git a/Mac/Python/macmain.c b/Mac/Python/macmain.c
index 0498be4..ad0d82b 100644
--- a/Mac/Python/macmain.c
+++ b/Mac/Python/macmain.c
@@ -38,6 +38,13 @@
 #include <Windows.h>
 #include <Fonts.h>
 #include <Balloons.h>
+#if TARGET_API_MAC_CARBON
+#include <CFBundle.h>
+#include <CFURL.h>
+#include <CFString.h>
+#include <CFBase.h>
+#include <CFArray.h>
+#endif /* TARGET_API_MAC_CARBON */
 #ifdef USE_APPEARANCE
 #include <Gestalt.h>
 #include <Appearance.h>
@@ -487,7 +494,7 @@
 
 #endif /* USE_MAC_APPLET_SUPPORT */
 
-#if TARGET_API_MAC_OSX
+#if TARGET_API_MAC_OSX /* Really: TARGET_API_MAC_CARBON */
 
 static int
 locateResourcePy(char * resourceName, char * resourceURLCStr, int length) {
@@ -495,45 +502,57 @@
     CFURLRef URL, absoluteURL;
     CFStringRef filenameString, filepathString, rsrcString;
     CFIndex size, i;
-    CFArrayRef arrayRef;
-    Boolean success = 0;
-
-    /* Create a CFString with the resource name in it */
-    rsrcString = CFStringCreateWithCString(0, resourceName, kCFStringEncodingMacRoman);
+    CFArrayRef arrayRef = NULL;
+    int success = 0;
+    
+#if TARGET_API_MAC_OSX
+	CFURLPathStyle thePathStyle = kCFURLPOSIXPathStyle;
+#else
+	CFURLPathStyle thePathStyle = kCFURLHFSPathStyle;
+#endif
 
     /* Get a reference to our main bundle */
     mainBundle = CFBundleGetMainBundle();
 
-    /* Look for py files in the main bundle by type */
-    arrayRef = CFBundleCopyResourceURLsOfType( mainBundle, 
-            CFSTR("py"), 
-           NULL );
+	/* If we are running inside a bundle, look through it. Otherwise, do nothing. */
+	if (mainBundle) {
+	    /* Create a CFString with the resource name in it */
+	    rsrcString = CFStringCreateWithCString(0, resourceName, kCFStringEncodingMacRoman);
 
-    /* See if there are any filename matches */
-    size = CFArrayGetCount(arrayRef);
-    for (i = 0; i < size; i++) {
-        URL = CFArrayGetValueAtIndex(arrayRef, i);
-        filenameString = CFURLCopyLastPathComponent(URL);
-        if (CFStringCompare(filenameString, rsrcString, 0) == kCFCompareEqualTo) {
-            /* We found a match, get the file's full path */
-            absoluteURL = CFURLCopyAbsoluteURL(URL);
-            filepathString = CFURLCopyFileSystemPath(absoluteURL, kCFURLPOSIXPathStyle);
-            CFRelease(absoluteURL);
+	    /* Look for py files in the main bundle by type */
+	    arrayRef = CFBundleCopyResourceURLsOfType( mainBundle, 
+	            CFSTR("py"), 
+	           NULL );
 
-            /* Copy the full path into the caller's character buffer */
-            success = CFStringGetCString(filepathString, resourceURLCStr, length,
-                                        kCFStringEncodingMacRoman);
+	    /* See if there are any filename matches */
+	    size = CFArrayGetCount(arrayRef);
+	    for (i = 0; i < size; i++) {
+	        URL = CFArrayGetValueAtIndex(arrayRef, i);
+	        filenameString = CFURLCopyLastPathComponent(URL);
+	        if (CFStringCompare(filenameString, rsrcString, 0) == kCFCompareEqualTo) {
+	            /* We found a match, get the file's full path */
+	            absoluteURL = CFURLCopyAbsoluteURL(URL);
+	            filepathString = CFURLCopyFileSystemPath(absoluteURL, thePathStyle);
+	            CFRelease(absoluteURL);
 
-            CFRelease(filepathString);
-        }
-        CFRelease(filenameString);
-    }
-    CFRelease(rsrcString);
-    CFRelease(arrayRef);
+	            /* Copy the full path into the caller's character buffer */
+	            success = CFStringGetCString(filepathString, resourceURLCStr, length,
+	                                        kCFStringEncodingMacRoman);
 
+	            CFRelease(filepathString);
+	        }
+	        CFRelease(filenameString);
+	    }
+		CFRelease(arrayRef);
+	    CFRelease(rsrcString);
+	}
     return success;
 }
 
+#endif /* TARGET_API_MAC_CARBON */
+
+#if TARGET_API_MAC_OSX
+
 int
 main(int argc, char **argv)
 {
@@ -580,7 +599,16 @@
 	int argc;
 	char **argv;
 	
+	static char scriptpath[1024];
+	char *script = NULL;
+
 	init_common(&argc, &argv, 0);
+
+#if TARGET_API_MAC_OSX /* Really: TARGET_API_MAC_CARBON */
+	/* If we are running inside of a bundle, and a __main__.py is available, use it */
+	if (locateResourcePy("__main__.py", scriptpath, 1024))
+		script = scriptpath;
+#endif
 	
 	if ( argc > 1 ) {
 		/* We're running a script. Attempt to change current directory */
@@ -603,7 +631,7 @@
 			exit(0);
 		}
 	}
-	Py_Main(argc, argv, NULL);
+	Py_Main(argc, argv, script);
 }
 #endif /* TARGET_API_MAC_OSX */