Help to use QFileDialog.

luguecos

Hello, i'm still learning how to use pyqt5 and i'm trying to make a plot application for myself. To plot my graphs I have to load data from a file. I did make a button for this purpose. The goal is to click the button to open a fileDialog window.

Here is a sample of the code in this regard:

from PyQt5 import QtWidgets, QtCore, QtGui, Qt

class Ui_MainWindow(QtWidgets.QWidget):    
    def setupUi(self, MainWindow):
        
        MainWindow.setObjectName("MainWindow")
        MainWindow.setWindowTitle("L Plot Beta v1.0")
        MainWindow.resize(800,600)
       
        Ui_MainWindow().loadDataButton()

    def loadDataButton(self):
        self.load_data_button = QtWidgets.QPushButton(MainWindow)
        self.load_data_button.setGeometry(QtCore.QRect(430, 100, 100, 30))
        self.load_data_button.setText("Load Data")
        
        self.load_data_button.clicked.connect(self.openFile())

    def openFile(self):
        fileName, _ = QtWidgets.QFileDialog.getOpenFileName(self, 'Open File', ' ', 'All Files (*);;Text Files (*.txt)')
        if fileName:
            print(fileName)

if __name__ == "__main__":

    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    Ui_MainWindow().setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

When I run this code the File Dialog box pops up before the main window. It is suppose to open the main window, then when I click the button it shows de File dialog box.

What I'm doing wrong?

Thanks in advance!

luguecos

I got it. The problem is that a lambda function was necessary when calling the method clicked.connect

just change the line

self.load_data_button.clicked.connect(self.openFile())

to

self.load_data_button.clicked.connect(lambda: self.openFile())`

jsulm

@luguecos said in Help to use QFileDialog.:

self.load_data_button.clicked.connect(self.openFile())

Here you're calling the slot. It should be:

self.load_data_button.clicked.connect(self.openFile)

luguecos

@jsulm When I call that way the button doesn't do anything