PyQt5 : How to use progress bar in PyQt5?

Question

See my code and tell me how do I set progress bar to the -dollar()- function and progress bar start with doing the function and finished with it. see my code at the continue:

from PyQt5.QtWidgets import (QWidget,QApplication,QTextEdit,
    QInputDialog,QPushButton,QVBoxLayout,QProgressBar)
import sys

class Tbx(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.vbox = QVBoxLayout()
        self.btn = QPushButton('ClickMe',self)
        self.btn.clicked.connect(self.dollar)
        self.te = QTextEdit(self)
        self.prgb = QProgressBar(self)#How to set this to doing something?
        self.vbox.addWidget(self.te)
        self.vbox.addWidget(self.btn)
        self.vbox.addWidget(self.prgb)
        self.setLayout(self.vbox)
        self.setGeometry(300,300,400,250)
        self.setWindowTitle('Application')
        self.show()
    def dollar(self):#Like doing this set progress bar to this
        text_1_int , ok = QInputDialog.getInt(self,'HowMany?','Enter How Many dollar do you want ?')
        if not ok:
            return
        current_lines = self.te.toPlainText().split('\n')
        new_lines = list()
        for dollar_counter in range(1,text_1_int+1):
            word = '$'*dollar_counter
            new_lines += [word + text for text in current_lines]
        self.te.setPlainText('\n'.join(new_lines))
if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Tbx()
    sys.exit(app.exec_())

Answer 1

You can set the maximum value of the progress control to the value entered in your input window and then simply use setValue to increase the progress bar, however, this will block the UI for very large calculations, so you might want to also move your method to a new thread and report progress to the UI using a signal, here is the full example:

from PyQt5.QtCore import QThread, pyqtSignal
from PyQt5.QtWidgets import (QWidget, QApplication, QTextEdit, QInputDialog, QPushButton, QVBoxLayout, QProgressBar)
import sys


class DollarCalculation(QThread):
    reportProgress = pyqtSignal(int, list)
    calculationFinished = pyqtSignal()

    def __init__(self, numDollars, currentLines):
        super().__init__()

        self.numDollars = numDollars
        self.currentLines = currentLines

    def run(self) -> None:
        for dollar_counter in range(1, self.numDollars + 1):
            word = '$' * dollar_counter
            self.reportProgress.emit(dollar_counter + 1, [word + text for text in self.currentLines])

        self.calculationFinished.emit()


class Tbx(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()

        self.dollarCalculation = None

    def initUI(self):
        self.vbox = QVBoxLayout()
        self.btn = QPushButton('ClickMe', self)
        self.btn.clicked.connect(self.dollar)
        self.te = QTextEdit(self)
        self.prgb = QProgressBar(self)
        self.vbox.addWidget(self.te)
        self.vbox.addWidget(self.btn)
        self.vbox.addWidget(self.prgb)
        self.setLayout(self.vbox)
        self.setGeometry(300, 300, 400, 250)
        self.setWindowTitle('Application')


    def dollar(self):
        text_1_int, ok = QInputDialog.getInt(self, 'HowMany?', 'Enter How Many dollar do you want ?')
        if not ok:
            return

        self.btn.setEnabled(False)

        self.prgb.setMaximum(text_1_int + 1)
        self.dollarCalculation = DollarCalculation(text_1_int, self.te.toPlainText().split('\n'))
        self.dollarCalculation.reportProgress.connect(self.progress)
        self.dollarCalculation.calculationFinished.connect(self.calculationFinished)
        self.dollarCalculation.start()

    def progress(self, value, newLines):
        self.te.append('\n'.join(newLines))
        self.prgb.setValue(value)


    def calculationFinished(self):
        self.btn.setEnabled(True)


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Tbx()
    ex.show()
    sys.exit(app.exec_())