QDialog blocking main thread?

by Martin Fitzpatrick Last updated PyQt5 FAQ
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anonymous | 2020-05-11 07:08:24 UTC | #1

1st: This is a great tutorial! Probably one of the best ones I have ever seen. 2nd: I tried to create a little GUI with your code, but I ran into a problem I cannot solve. I added a class for giving back the status to the GUI,

python 
self.STATI = [Status(ID=i, callback=self.postStatus) for i in range(SLOTS)]
...
class Main():
    def Button_clkd(self):
        self.workFunc(process, "parameter")


    def workFunc(self, *argv):
        self.ui.resultWindow(self)
        self.timer.setInterval(2000)

        for job in self.jobs:
            self.total_jobs += 1
            self.STATI[job].reset()
            worker = Worker(argv[0], self.jobs[job], val, self.STATI[job])
            worker.signals.result.connect(self.postResult)
            self.threadpool.start(worker)

    def postStatus(self, STATUS):
        #print("STATUS:", STATUS.id)
        lables_list = self.ui.resultBox.findChildren(QtWidgets.QLabel)    
        lables_list[STATUS.id].setText("Slot "+ str(STATUS.id) +" job: "+ STATUS.status)
        if STATUS.status == True:
            self.timer.setInterval(500)

class Status():
    def  **init** (self, ID, callback=lambda callbackparameter: None):
        self.status = ""
        self.callback = callback
        self.id = ID

    def update(self, callbackparameter):
        self.status = callbackparameter
        self.callback(self)

    def reset(self):
        self.status = ""

In another file I have a function that simply prints or puts a value to STATUS.status and this sometimes just does nothing - I seem not to be able to figure out why. Can you maybe point me in the right direction?

Is it possible that my QDialog blocks all my input? Is this because it is executed by exec_()?

I already have samples of code where I can dynamically update the labels in the QDialog class, but I cannot figure out what makes it "stop" - meaning, that after I closed the QDialog window, all my prints are shown in the console - but nothing before (not even errors).

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QDialog blocking main thread? was written by Martin Fitzpatrick .

Martin Fitzpatrick has been developing Python/Qt apps for 8 years. Building desktop applications to make data-analysis tools more user-friendly, Python was the obvious choice. Starting with Tk, later moving to wxWidgets and finally adopting PyQt.

QDialog blocking main thread? was published in faq on (updated ) . Feedback & Corrections welcome in our public issue tracker.

 pyqt5 pyqt threading threads lock qdialog python qt qt5