QProcess can launch programs but not python (command line)

[jonasqt]

The following code is failing to launch the python command line.

QProcess *myProcess = new QProcess(this);
myProcess->start("\"C:\\Program Files\\Python27\\python.exe\"");

If I replace python27 with (for example)

myProcess->start("\"C:\\Program Files\\Notepad++\\notepad++.exe\"")

notepad opens. Why is my program able to launch notepad but not Python Command Line?

I tried using startDetached() but that didn't make a difference.

QProcess::Error() gives me error 5: unknown error.

[edit koahnig: code tags added]

[koahnig]

@jonasqt

You should use codetags (right button above the input pane) for all your code snippets. Otherwise your code lines are hard to read.

[VRonin]

what does qDebug() << QFile::exists("\"C:\\Program Files\\Python27\\python.exe\""); print? (I'm not taking the piss, I promise)

[jonasqt]

@VRonin it prints false. so that means that my the python.exe file doesn't exist, correct? Is there another explanation for this other than that I might have errors in my filepath? Because I cant see where it could be wrong.

[jonasqt]

@VRonin I maneged to fix it so that qDebug << exists() now returns true. Python is still not launching though.

[SGaist]

Hi,

What are you expecting when calling python like that ?

[jonasqt]

@SGaist I'm expecting the python command line to launch.

[jonasqt]

@SGaist is it wrong to expect the command line to actually open as a window? I've just noticed that I can open most applications except command lines. (When I try to launch cmd.exe, git-cmd.exe, python.exe nothing happens while I can open e.g. chrome.exe, git-bash.exe, notepad.exe)

[jsulm]

@jonasqt said in QProcess can launch programs but not python (command line):

is it wrong to expect the command line to actually open as a window

Yes, it is. Command line tools do not have any windows - they run in a shell/terminal (terminal has a window). On Windows you can try pythonw.exe instead of python.exe. Or you start cmd.exe and pass the path to Python executable with -c as parameter to cmd.exe