How to open *.jpg or *.png files?

[elypheldia]

When I try to open a file from interface, I had this error. How can I fix it ?

QWidget: Must construct a QApplication before a QWidget

And I had this TypeError

TypeError: getOpenFileName(parent: QWidget = None, caption: str = '', directory: str = '', filter: str = '', initialFilter: str = '', options: Union[QFileDialog.Options, QFileDialog.Option] = 0): argument 1 has unexpected type 'Ui_MainWindow'
My code:

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QFileDialog


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.setEnabled(True)
        MainWindow.resize(1214, 600)
        MainWindow.setStyleSheet("background-color: rgb(211, 215, 207);")
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")



        
        self.label_source = QtWidgets.QLabel(self.centralwidget)
        self.label_source.setGeometry(QtCore.QRect(0, 160, 550, 400))
        self.label_source.setText("")
        self.label_source.setObjectName("label_source")
        
        
        
        
        
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.actionOpen_Source = QtWidgets.QAction(MainWindow)
        icon = QtGui.QIcon.fromTheme("folder-open")
        self.actionOpen_Source.setIcon(icon)
        font = QtGui.QFont()
        self.actionOpen_Source.setFont(font)
        self.actionOpen_Source.setShortcutContext(QtCore.Qt.WindowShortcut)
        self.actionOpen_Source.setAutoRepeat(True)
        self.actionOpen_Source.setVisible(True)
        self.actionOpen_Source.setMenuRole(QtWidgets.QAction.TextHeuristicRole)
        self.actionOpen_Source.setObjectName("actionOpen_Source")
        self.actionOpen_Source.triggered.connect(self.openSource)
        
        

    
       
        
    **def openSource(self):
        openFile=QFileDialog.getOpenFileName(self,'Open Source', '../images', 'Image Files (*.jpg,*.png)')
        fname = open(openFile)
        self.label_source.setPixmap(QtGui.QPixmap(fname))**

        
if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

[JonB]

@elypheldia said in How to open *.jpg or *.png files?:

argument 1 has unexpected type 'Ui_MainWindow'

Your class Ui_MainWindow(object) means Ui_MainWindow does not derive from QWidget. QFileDialog.getOpenFileName(self will therefore fail. You probably want to pass MainWindow instead of self.

QWidget: Must construct a QApplication before a QWidget: fix first above, maybe goes away? Else determine where it comes from (e.g. run under debugger).