Pyqt: How to show a QFileDialog?

[robgeek]

Hi!

I would like to choose a path for a file that will be downloaded from internet. To do that I tried to create a button, when pressed will open a QFileDialog so I can choose the path. To make my initial GUI i'm using Qt Designer 5.7 and pyqt5.

The output when i hit "Folder" button:

Traceback (most recent call last):
File "teste.py", line 49, in destination
self.folderPath = QtWidgets.QFileDialog.getExistingDirectory(self, 'Select folder');
TypeError: getExistingDirectory(parent: QWidget = None, caption: str = '', directory: str = '', options: Union[QFileDialog.Options, QFileDialog.Option] = QFileDialog.ShowDirsOnly): argument 1 has unexpected type 'Ui_MainWindow'
Aborted (core dumped)

from PyQt5 import QtCore, QtGui, QtWidgets
#...
self.destinoButton.clicked.connect(self.destination)
#...
    def destination( self ):
        self.folderPath = QtWidgets.QFileDialog.getExistingDirectory(self, 'Select folder');

from PyQt5 import QtCore, QtGui, QtWidgets
#...
self.destinoButton.clicked.connect(self.destination)
#...
    def destination( self ):
        self.folderPath = QtWidgets.QFileDialog.getExistingDirectory(self, 'Select folder');

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How can I fix it?

[anda_skoa]

Well, as Python told you, the first argument of getExistingDirectory() is not what it expects.

You pass an object of type "Ui_MainWindow" and it expects a QWidget.

Did you derive from the designer generated class instead of using it?

Cheers,
_

[robgeek]

Here my class definition:

from PyQt5 import QtCore, QtGui, QtWidgets
 
class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        #...
        self.destinoButton.clicked.connect(self.destination)
        #...
    def destination( self ): #Now instead of "self" is "MainWindow".
        self.folderPath = QtWidgets.QFileDialog.getExistingDirectory(self, 'Select folder');

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        #...
        self.destinoButton.clicked.connect(self.destination)
        #...
    def destination( self ): #Now instead of "self" is "MainWindow".
        self.folderPath = QtWidgets.QFileDialog.getExistingDirectory(self, 'Select folder');

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I changed "self" to "MainWindow" and is working fine. I have no idea why, by is working. I'm newbie in Python.

[anda_skoa]

This looks like you are changing the code that has been generated from the designer's output instead of just using that code inside MainWindow.

Which is usually a very bad idea as this means you can no longer use designer for that form, i.e. can't add/change/remove anything with designer, as the next code generation step would then overwrite all your manual code changes.

I recommend considering to use this properly.

Cheers,
_