calling python from qt c++

[marwa ahmed]

hi,

i want to call a python code from qt c++ and give it some float parameters, how can i do this in qt and how should the python file which is call look like?

[JonB]

@marwa-ahmed
Depends whether you intend the Python code to be an external script or an embedded interpreter in the Qt C++ app. Which probably depends on what you want it to do. Always assuming you don't want your Qt app to be written in Python + Qt itself.

[marwa ahmed]

python code is external script not embedded in the qt and it takes parameters 4 float variables so i want to call this script which takes the input and do lots of work and algorithm depends on many libraries in python the return a result
i tried first a code like this to ensure that qt can call a python file
QStringList params;
QString pythonPath = "C:/Python27/python.exe";
QString pythonScript = "C:/Users/maboelamayem/PycharmProjects/testqt.py";

    params << pythonScript;
    p.start(pythonPath, params);
    p.waitForFinished(-1);
    QString p_stdout = p.readAll();
    QString p_stderr = p.readAllStandardError();
    if(!p_stderr.isEmpty())
       qDebug()<<"Python error:"<<p_stderr;
    qDebug()<<"Python result="<<p_stdout; 

but it gives error : Python error: "C:\Python27\python.exe: can't open file 'C:/Users/maboelamayem/PycharmProjects/testqt.py': [Errno 2] No such file or directory\r\n"

[JonB]

@marwa-ahmed said in calling python from qt c++:

can't open file 'C:/Users/maboelamayem/PycharmProjects/testqt.py': [Errno 2] No such file or directory\r\n"

So that file does not exist. Nothing we can help with if it does not.

[marwa ahmed]

okay i missed main in the python code but now my python code is :
if name == "main":
print "marwa"

but the error in qt is

Python error: "C:\Python27\python.exe: can't find 'main' module in 'C:/Users/maboelamayem/PycharmProjects/testqt'\r\n"

so am i writing the function in python code wrongly?

[marwa ahmed]

hey, i solved this problem but i want now to send parameters to the main function in the python code but p.start() is not used for this so what is the other option to send parameters or arguments to the python function

[JonB]

@marwa-ahmed said in calling python from qt c++:

but p.start() is not used for this

Yes it is. Why not look at the docs: https://doc.qt.io/qt-5/qprocess.html#start and https://doc.qt.io/qt-5/qprocess.html#running-a-process

[kaif]

please can I get your contact number I am working on an industrial robot and I am stuck with the same thing you did! It is urgent. Thank you