Run python script in Qt

[aha_1980]

@J.Hilk said in Run python script in Qt:

usually yes, but in this case you're trying to start a System program from the OS

As said, the path for QProcess should work with forward slash. The path for the parameter (the script) probably not.

[NotYourFan]

@J-Hilk thank you for the stackoverflow link, i've seen it and try it.
@aha_1980 i test python -c 'print "Hello World"' --> i get Nothing.

[aha_1980]

@NotYourFan said in Run python script in Qt:

@aha_1980 i test python -c 'print "Hello World"' --> i get Nothing.

How did you test it?

[NotYourFan]

put python -c 'print "Hello World"' in p.start

[Pablo J. Rogina]

@NotYourFan just in case, you may want to use Python embedded in your Qt application...

[jsulm]

@NotYourFan It doesn't work like this. You have to put the command as first parameter to start() and all parameters for the command as parameter list.

[Gojir4]

@jsulm Are you sure about that ?
from Qt Doc:

QProcess process;
process.start("del /s *.txt");

[NotYourFan]

@jsulm i readed in the Qt Doc.
@Gojir4 you are right.
@Pablo-J-Rogina thx for your Suggestion … but i should / want to do it with QProcess …

[SGaist]

Hi,

@NotYourFan just in case, did you try to compare the environment variables of your QProcess object and the one you have when running e.g. from a terminal ?

@Gojir4 You are right about that specific overload, but the documentation also states that this overload should be avoided if possible.

[Gojir4]

@SGaist My bad. Thanks for clarification !

[JonB]

@NotYourFan
I am lost as to where you are now.

Assuming it's still crashing --- is that right? --- surely you want to break it down to simplify now. Start with:

    params << "-V";
    p.start("C:\\development\\Python\\Python37\\python.exe", params);
    p.waitForFinished(-1);
    QString p_stdout = p.readAll();

What exactly happens?

[NotYourFan]

@JonB, i get a error Message: ….

ModuleNotFoundError: No module named 'encodings'

[JonB]

@NotYourFan
OK! So, you can forget about your createJSON.py script and anything it does.

I don't know why you get this when spawning from Qt but not when running your python.exe directly from a command prompt. Either it's something to do with it sending output to a pipe you are reading from, or it's to do with your general Python environment being different between the two situations.

You want now to Google for python ModuleNotFoundError: No module named 'encodings'. There are posts/suggestions. Looks to me like it might be to do with whether you are using a virtual environment or not, but I'm sure one of the hits will sort you out....

[aha_1980]

@JonB I can imagine that the Environment inside Qt Creator is different (e.g. PATH) and therefore other (incompatible) executables and libraries are found.

@NotYourFan: You should carefully check the Run Environment variables inside Qt Creator, especially PATH. That's all I can say for now.

Regards

[NotYourFan]

@JonB, when i run my createJSON.py from the console, everything working fine.
@aha_1980 thanks !! I will checked immediately.

[NotYourFan]

@aha_1980 !!!!!
Thank you :=)

That was the Problem.
I use for "Debug" MinGW (MinGW included python2.7 and set a PYTHON variable)
So now i tried like this:

QProcess cmd;
QProcessEnviroment env = QProcessnviroment::systemEnviroment();
QProcessEnviroment envUpdate;

envUpdate.inser("PATH", env.value("PATH"));
cmd.setProcessEnviroment(envUpdate)
cmd.start("python.exe C:\\Users\\...\\Desktop\\...\\createJSON.py")
cmd.waitForFinished();

Now it works :)

Thank you @all for your standby