[Python] QFileDialog not closing after file selection

I have a simple function that opens a file dialog using pyqt6 to select a file. The function works, but the dialog hangs after being called and I'm not sure why it's not getting automatically closed when the file is selected.

def ui_find_file(title=None, initialdir=None, file_type=None):
import os
from PyQt6.QtWidgets import QApplication, QFileDialog

app = QApplication([])
file_dialog = QFileDialog()
file_dialog.setFileMode(QFileDialog.FileMode.ExistingFile)

if file_type:
filter = f"{file_type} files (*.{file_type})"
file_dialog.setNameFilter(filter)
else:
file_dialog.setNameFilter("All files (*);;")

if initialdir is None:
initialdir = os.getcwd()
elif initialdir == '~':
initialdir = os.path.expanduser('~')

file_dialog.setDirectory(initialdir)

if title:
file_dialog.setWindowTitle(title)

if file_dialog.exec():
file_path = file_dialog.selectedFiles()[0]
print(f"Selected {file_path}")
file_dialog.deleteLater() # Clean up the file dialog window
app.quit() # Exit the event loop
return file_path
else:
print("No file selected")
file_dialog.deleteLater() # Clean up the file dialog window
app.quit() # Exit the event loop
return None



When I try the first lines in the command line

from PyQt6.QtWidgets import QApplication, QFileDialog

app = QApplication([])
file_dialog = QFileDialog()
file_dialog.setFileMode(QFileDialog.FileMode.ExistingFile)


and I use either file_dialog.open() or file_dialog.exec(), I can select a file and the dialog closes without freezing the python instance. I don't even have to call file_dialog.deleteLater() for it to close itself.

When I try to use this from another script, for example doing:

from utils import ui_find_file
ui_find_file()


It produces the freezing behavior.

Updates on things I have tried but didn't work


I am running this in python 3.10, Ubuntu 20.04, from a terminal.

• I have tried using destroy() instead of destroyLater().
• I have tried using app.processEvents() below destroy() with del(app)

The reason I am creating app = QApplication([]) was because when I didn't, I got QWidget: Must construct a QApplication before a QWidget (which I can reproduce by commenting out the line)

Python 3.10.6 (main, Mar 10 2023, 10:55:28) [GCC 11.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from utils import ui_find_file
>>> ui_find_file()
QWidget: Must construct a QApplication before a QWidget
Aborted (core dumped)

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