How do I get my QProgressDialog to show up when I don't know how long it will take?

Question

I am using subprocess.call to run a command prompt command that takes a while (>5 minutes) to run:

subprocess.call([command, param1, param2], cwd=cwdDir)

I want to use a QProgressDialog to show that this command is running. I did this:

        progressDialog = QProgressDialog("Executing...", "", 0, 0)
        progressDialog.setCancelButton(None)
        progressBar = QProgressBar(progressDialog)
        progressBar.setMinimum(0)
        progressBar.setMaximum(0)
        progressDialog.setBar(progressBar)
        progressDialog.show()
        subprocess.call([command, param1, param2], cwd=cwdDir)
        progressDialog.close()

When I run my program, this is what shows up:

After a while, my commands finish executing and the window closes. How do I get it so that you can see the QProgressBar in the window?

Answer 1

You can use Qthread so program's event loop is not blocked. And increase the value of the progress bar either by a timer or read information from subprocess.call or just show the busy icon in the process bar.