PyQt GUI冻结，直到线程完成，同时在Python中进行多线程处理

Question

The code is pretty heavy so I will just post some snippets.

class Program(QtGui.QWidget):
    def __init__(self, parent=None):
        super(Program, self).__init__(parent)

...

def main():   
    app = QtGui.QApplication(sys.argv)
    global ex
    ex = Program()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

And in between I have a bunch of labels, text fields, buttons and 4 QListWidgets inside sublayouts, these sublayouts are added to the grid.

I'm launching variable number of threads depending on input. Normally 4 threads. They are launched in own class:

class myThread(Thread):
    def __init__(self, arguments, more_arguments):
        threading.Thread.__init__(self)

    def work_it(self, argument, more_arguments):
        Program.some_function_in_Program_class(ex, arguments)

And from there I call functions inside the Program() class to do the actual changes to the GUI.

Program.generate_results(ex, arguments, arguments2, more_arguments)

In the end it comes down to a list I iterate over and whether I print each element or I use:

my_listbox.addItem(item)

It freezes the GUI until all 4 threads are finished going through the list. Then all the results appear together instead of appearing one by one.

I have done this in Tkinter and I could see one by one list item appear in the ListBox widgets dynamically, without freezing the GUI.

As for managing threads what I'm doing is I'm iterating over a list and according to its length I make a number of threads:

threadlist = []
for i in self.results:
    sub_thread = myThread(i, self.results[i])
    self.threadlist.append(sub_thread)
swapAndWaitThread = spawnAndWaitThreadsThread(self.threadlist)
swapAndWaitThread.start()

I do this to be able to manage these 4 threads and be able to tell when they are finished.

class spawnAndWaitThreadsThread(Thread):
    def __init__(self, threadlist):
        threading.Thread.__init__(self)
        self.threadlist = threadlist

    def run(self):
        for thread in self.threadlist:
            thread.start()

        for thread in self.threadlist:
            thread.join()

    print "threads finished.. do something"

What am I doing wrong?

Answer 1

I resolved this issue by adding a very simple function in the main Program() class which has only one job - to start a very simple thread which in turn goes back to Program() class and calls a function there which then starts constructing my threads list, sending them to another thread class, etc.

As a result GUI is not freezing anymore.