Embedding Python does not throw an error, but the program crashes anyways
-
@SGaist Hi, Thanks for the response. The python files are in the same folder as my executable. How would I check for null objects? Am I not doing that already? I thought that
if (PyCallable_Check(pFunc)) { PyObject_CallObject(pFunc, NULL); } else { PyErr_Print(); }Would print out the error message that is returned, is that not correct?
@lfreeman6490 Have you verified that the pointers are not null?
-
@lfreeman6490 Have you verified that the pointers are not null?
@eyllanesc How would I check for that? Is my if loop at the end of my code not checking for error messages?
-
@eyllanesc How would I check for that? Is my if loop at the end of my code not checking for error messages?
@lfreeman6490 PyErr_Print only returns python errors, it does not check memory.
what is the output of:
qDebug() << pName << pModule << pDict;before
PyDict_GetItemString(...)? -
@lfreeman6490 PyErr_Print only returns python errors, it does not check memory.
what is the output of:
qDebug() << pName << pModule << pDict;before
PyDict_GetItemString(...)?@eyllanesc There is no difference in the output when entering that line. I cleaned, reran qmake, rebuilt, then ran directly from the executable as well as from qtcreator. The output just says
The program has finished unexpectedly -
@eyllanesc There is no difference in the output when entering that line. I cleaned, reran qmake, rebuilt, then ran directly from the executable as well as from qtcreator. The output just says
The program has finished unexpectedly@lfreeman6490 I never said that was the solution, do not rush. I'm just asking for some debugging information to analyze the cause of the error.
-
@lfreeman6490 I never said that was the solution, do not rush. I'm just asking for some debugging information to analyze the cause of the error.
@eyllanesc Okay, thanks. I just wanted to clearly show what the error message was and what I had done already
-
@eyllanesc Okay, thanks. I just wanted to clearly show what the error message was and what I had done already
@lfreeman6490 Comment on the line that generates the error and tell me what is printed on the console
-
@lfreeman6490 Comment on the line that generates the error and tell me what is printed on the console
@eyllanesc Okay, commenting out that line gives me hex code errors
0x67b0128 0x0 0x57290610 -
@eyllanesc Okay, commenting out that line gives me hex code errors
0x67b0128 0x0 0x57290610@lfreeman6490 From the print we can see that
pModuleis null, so you get this behavior.Change to:
if(!(pModule = PyImport_Import(pName))){ PyErr_Print(); return; } -
@lfreeman6490 From the print we can see that
pModuleis null, so you get this behavior.Change to:
if(!(pModule = PyImport_Import(pName))){ PyErr_Print(); return; }@eyllanesc Where in the code should I add that? Should that be directly after creating pModule? Or at the very last spot in the code?
-
@eyllanesc Where in the code should I add that? Should that be directly after creating pModule? Or at the very last spot in the code?
@lfreeman6490 Change
pModule = PyImport_Import(pName); -
@lfreeman6490 Change
pModule = PyImport_Import(pName);@eyllanesc Okay so by changing that it is no longer crashing, but it is not calling my function. The function is a simple test function that should return a number
def test_function(): return 7 -
@eyllanesc Okay so by changing that it is no longer crashing, but it is not calling my function. The function is a simple test function that should return a number
def test_function(): return 7@lfreeman6490 It seems that you have not understood the problem. Your code has not imported the module so pModule is null.
-
I am trying to embed a python interpreter into my c++ gui. I am including Python.h and then in my function
void pl::on_pb_connect_disconnect_clicked() { PyObject* pName, *pModule, *pDict, *pFunc; Py_Initialize(); std::string filename = "test_python_file.py"; const char* cstr1 = filename.c_str(); pName = PyUnicode_FromString(cstr1); pModule = PyImport_Import(pName); pDict = PyModule_GetDict(pModule); std::string function_name = "test_function"; const char* cstr = function_name.c_str(); pFunc = PyDict_GetItemString(pDict, cstr); if (PyCallable_Check(pFunc)) { PyObject_CallObject(pFunc, NULL); } else { PyErr_Print(); } Py_Finalize(); }The basic idea is that once the 'connect' button is hit, it calls test_function in test_python_file.py. It builds and runs successfully, once it is launched and I hit the 'connect' button, the program crashes. I have cleaned, rebuild, ran qmake, etc. Running in debug mode gives me a division by 0 error. If I comment out the code line by line I see that the errors comes from
pDict = PyModule_GetDict(pModule);Once that line is used again, the program crashes.
@lfreeman6490 said in Embedding Python does not throw an error, but the program crashes anyways:
std::string filename = "test_python_file.py"; const char* cstr1 = filename.c_str(); pName = PyUnicode_FromString(cstr1); if(!(pModule = PyImport_Import(pName))){ PyErr_Print(); return; }From the
0x0output you really should be able to understand thatPyImport_Import(pName)returnednullptr. That means yourtest_python_file.pycould not be loaded, Either the file could not be found, or there is some problem loading it. Hopefully thePyErr_Print();gave some clue as to why, but you never said anything about what it output.Start by changing your
test_python_file.pyto the full path to where that file is.
