There is a function (LoadData) for loading large data (taken from the database (SQlite)) into a text file ( fout ) with filling in the corresponding indicator ( self.ui.progressBar ). When executing the function, the window application starts “Not responding” and freezes (since the cycle time is ~ 3 minutes depending on the size of data ) while the cycle is being executed ( for line in data ). Accordingly, the indicator value all this time is 0%. What are the solutions to this problem?

def LoadData(self, data): nof = self.ui.lineEdit_22.text() + '.txt' #Имя файла вводит пользователь fout = open(nof, 'w') self.step = 0 #Значение индикатора percent = len(data)/100 #Количество строк в 1% coun = 0 #Счётчик строк for line in data: for i in range(10): fout.write(str(line[i])) fout.write(' ') fout.write('\n') coun = coun + 1 if coun == percent: coun = 0 self.step = self.step + 1 self.ui.progressBar.setValue(self.step) fout.close()

1 answer 1

Run a long process in QThread:

 import sys import time from PyQt5 import QtCore, QtWidgets class SlowTask(QtCore.QThread): updated = QtCore.pyqtSignal(int) running = False def __init__(self, *args, **kwargs): super(SlowTask, self).__init__(*args, **kwargs) self.percent = 0 self.running = True def run(self): while self.running: self.percent += 1 self.percent %= 100 self.updated.emit(int(self.percent)) time.sleep(0.1) def stop(self): self.running = False class MainWindow(QtWidgets.QMainWindow): def __init__(self, *args, **kwargs): super(MainWindow, self).__init__(*args, **kwargs) self.setupUi() def setupUi(self): self.setWindowTitle('Test') self.resize(446, 207) self.progressbar = QtWidgets.QProgressBar(self) self.progressbar.setGeometry(QtCore.QRect(40, 70, 381, 23)) self.progressbar.setProperty('value', 0) self.btn_start = QtWidgets.QPushButton('Start', self) self.btn_start.setGeometry(QtCore.QRect(110, 110, 75, 23)) self.btn_start.setEnabled(True) self.btn_start.clicked.connect(self.on_start) self.btn_stop = QtWidgets.QPushButton('Stop', self) self.btn_stop.setGeometry(QtCore.QRect(260, 110, 75, 23)) self.btn_stop.setEnabled(False) self.btn_stop.clicked.connect(self.on_stop) def toggle_buttons(self): self.btn_start.setEnabled(not self.btn_start.isEnabled()) self.btn_stop.setEnabled(not self.btn_stop.isEnabled()) def on_update(self, data): self.progressbar.setValue(data) # if data == 99: # self.on_stop() def on_start(self): self.toggle_buttons() self.task = SlowTask(self) self.task.updated.connect(self.on_update) self.task.start() def on_stop(self): self.task.stop() self.progressbar.setValue(0) self.toggle_buttons() if __name__ == '__main__': app = QtWidgets.QApplication(sys.argv) w = MainWindow() w.show() sys.exit(app.exec_())