Minimal code to run script in application

[Squal]

Hello,

I am trying to run python scripts from standard C++ application.
I have checked the code of the python application done by Nokia and tried to use the same "CSPyInterpreter" object but i always receive a KErrGeneral (-2) error!

Is there a minimal code available to run pyhton scripts from application?
Is there some "evident" requirements to follow?

Some others related question:
Is there a mean to give arguments to the python scripts?
Is it possible to exchange data between the python script and the application in both ways?

Squal.

[Squal]

I have found some code here:

http://wiki.forum.nokia.com/index.ph...ymbian_C%2B%2B

but unfortunately some variables are not defined...
-> pre_handler
-> aString

and i have not for the moment found explanatino about those methods PyDict_GetItemString and Py_BuildValue.

[nlsp]

.. and i have not for the moment found explanation about those methods PyDict_GetItemString and Py_BuildValue.

See Python C-API documentation

• PyDict_GetItemString
• Py_BuildValue

[janekw_]

First of all, here:

http://docs.python.org/ext/ext.html
http://docs.python.org/api/api.html

... you'll find most documentation including those functions you mentioned. Python/C in PyS60 uses essentialy the same API. Minor differences are more or less explained in 9th chapter of PyS60 docs.

Like you say, wiki example is flawed. I'll post mine, slightly corrected version:

#include <Python.h>
#include <CSPyInterpreter.h>
#include "Embedder.h"

void Embedder::Execute(const TDesC& aMethod, TDes& aOutput)
	{
	TInt retVal(KErrNone);
	 
	// Create a  Python interpreter
	CSPyInterpreter* it = CSPyInterpreter::NewInterpreterL();
	CleanupStack::PushL(it);
	
	// Save state of any current Python interpreter, and acquire the interpreter lock
	PyEval_RestoreThread(PYTHON_TLS->thread_state);
	
	char *module_name = "Embedded" ;
	const char *method = "eggsMaybe" ;
	char *response = "" ;
	
	TInt32 r_len = 0 ;
	PyObject *pModule = PyImport_ImportModule(module_name) ;
	if ( pModule != NULL )
		{
		PyObject *module_dict = PyModule_GetDict(pModule) ;
		PyObject *expression = PyDict_GetItemString(module_dict, method) ;
		PyObject *arglist = NULL;
		PyObject *result = PyEval_CallObject(expression, arglist);
		response = PyString_AsString( result ) ;
		r_len = strlen( response ) ;
		}
	
	// Make a Symbian descriptor pointer to the char * response
	TPtrC8 symResponse((TUint8*)response, r_len ) ;
	aOutput.Copy(symResponse);
	
	// Clean-up, and restore thread state
	PyEval_SaveThread();
	CleanupStack::PopAndDestroy(it);
	}

I'll also post an example of calling a script with arguments. It may be needlessly complicated, it's been a while, but I recall I had some difficulties with correct descriptors' format.

#include <Python.h>
#include <CSPyInterpreter.h>
#include <f32file.h>
#include "SMS.h"

void SMS::SendSMSL(const TDesC& aNumber, const TDesC& aMessage)
	{
	// Run python send sms code with arguments provided.
	CSPyInterpreter* it = CSPyInterpreter::NewInterpreterL();
	CleanupStack::PushL(it);

	// Run a script file with args.
	// ... Get a path to the script.
	_LIT(KScriptFile, "SendSMS.py");
	const TInt KMaxPathLength = 128;
	TBuf<KMaxPathLength> scriptPath;
	RFs fs;
	User::LeaveIfError(fs.Connect());
	CleanupClosePushL(fs);
	User::LeaveIfError(fs.CreatePrivatePath(EDriveC));
	User::LeaveIfError(fs.PrivatePath(scriptPath));
	scriptPath.Append(KScriptFile);
	CleanupStack::PopAndDestroy(&fs);
	
	// ... Prepare all args to 8b pointers.
	const TInt KForZeroTerminate = 1;
	HBufC8* scriptPath8bBuf = HBufC8::NewLC(scriptPath.Length() + KForZeroTerminate);
	TPtr8 scriptPath8b = scriptPath8bBuf->Des();
	scriptPath8b.Copy(scriptPath);
	char* scriptPathPtr = (char*)scriptPath8b.PtrZ();
	
	HBufC8* number8bBuf = HBufC8::NewLC(aNumber.Length() + KForZeroTerminate);
	TPtr8 number8b = number8bBuf->Des();
	number8b.Copy(aNumber);
	char* numberPtr = (char*)number8b.PtrZ();
	
	HBufC8* message8bBuf = HBufC8::NewLC(aMessage.Length() + KForZeroTerminate);
	TPtr8 message8b = message8bBuf->Des();
	message8b.Copy(aMessage);
	char* messagePtr = (char*)message8b.PtrZ();

	// ... Run the script.
	char* argv[3] = { scriptPathPtr, numberPtr, messagePtr };
	TInt pyError = it->RunScript(sizeof(argv) / sizeof(*argv) /* just for fun */, argv);
	User::LeaveIfError(pyError);
	
	// ... Cleanup a bit.
	CleanupStack::PopAndDestroy(message8bBuf);
	CleanupStack::PopAndDestroy(number8bBuf);
	CleanupStack::PopAndDestroy(scriptPath8bBuf);
	
	CleanupStack::PopAndDestroy(it);
	}

If the code won't work for you, let me know, cause I've only assumed it's in the working condition;>

[Squal]

Hello,

Thank you very much for your reply and for your example.

I have still one question.
The code "PyObject *pModule = PyImport_ImportModule(module_name)" always return a null pointer so the module is not found.

For me a module is a python script. Is it right?
I have checked Py_GetPath and this function returns c:\resource but even if my script is in c:\resource the pointer is null.

Do i must apply something more? Must the script include something special?

I have read documentation but for the moment i don't see an "evident" response.

[janekw_]

I've tested the first example now, all's well.
My 'Embedded.py' script:

def eggsMaybe():
    return 'eggs from embedded world'

indeed resides in the c:\resource dir on emulator. Other than that, I don't know what may be wrong.
I'm still working on PyS60_1.4.0 but I don't think that matters.

[Squal]

Hello,

With a simple script as your example, it's working!!

Something in my script puzzles the "import" phase...i will try to invesigate why.

Thank you very much
Squal.

[Squal]

Hello,

I have found the guilty!
I had "import appuifw" in my script. I used it before to allow user input...

Now the issue is definitely closed!