I experience crashes after certain conditions are met in my current project. It took me some time to really pinpoint the problem.
I’m using Python 3.11 with PySide6. In a nutshell, the app shows:
treeView (with QStandardItemModel)
tableView1 (with QAbstractTableModel)
tableView2 (with QAbstractTableModel and QSortFilterProxyModel)
Function-wise, everything works as intended. Basic funtionality:
User chooses item from treeView -> tableView1 shows all attributes inside the chosen object -> tableView2 shows contents of a SQL database for all entries matching the chosen object.
User can now interact with tableView1 + tableView2 (clicking, editing...)
Problem (click sequence):
Click on item in treeView -> tableView1 and 2 are updating
Click on column header in tableView2 (.setSortingEnabled(True))
Click on cell in tableView2 (just highlighting)
Click on different item in treeView -> tableView1 and 2 update
Click on column header in tableView2 again -> crash (mostly on the first click, but sometimes you can click a few times before it crashes)
Only this sequence leads to the crash. If you miss a step, it won’t crash. With “crash” I mean:
-
no exception is raised, the thread just closes
-
debugger doesn’t stop @exception, it just crashes
faulthandler stack trace doesn’t show too much info…
IMPORTANT: I already solved a very similar bug: Click sequence:
Click on item in treeView -> tableView1 and 2 are updating
Click on cell in tableView2 (just highlighting)
Click on different item in treeView -> crash (mostly on the first click, but sometimes you can click a few times before it crashes)
I noticed, after clicking the cell in tV2, if I click somewhere else (for example a cell in tV1), it then won’t crash when clicking treeView again. So my assumption was, there has to be something stored somewhere, when the cell in tV2 is clicked. After a quick research I tried deleting the selection data of tV2 before treeView clicking action is carried out:
selection_model_tV2 = self.ui.tabView_2.selectionModel()
selection_model_tV2.clear()
That worked!
So naturally my first approach (for the current bug) was to also clear the selection data of treeView, tV1, tV2 and a mix of those, but nothing worked out so far…
For the current one, I’m not sure which .selectionModel() is responsible (if any) for the bug, therefore I tried clearing treeView, tV1, tV2 and combinations.
Additional info:
If I disable QSortFilterProxy, both crashes wouldn’t happen…
Reproducible example:
import faulthandler
import sys
import pandas as pd
from PySide6.QtCore import QAbstractTableModel, QSortFilterProxyModel, Qt
from PySide6.QtGui import QStandardItem, QStandardItemModel
from PySide6.QtWidgets import (
QApplication,
QHBoxLayout,
QHeaderView,
QMainWindow,
QTableView,
QTreeView,
QWidget,)
faulthandler.enable()
class CustomTableModel(QAbstractTableModel):
def __init__(self, table_data=pd.DataFrame(), parent=None):
super(CustomTableModel, self).__init__()
self.table_data = table_data
self.parent = parent
def data(self, index, role):
value = self.table_data.iat[index.row(), index.column()]
if role == Qt.DisplayRole or role == Qt.EditRole:
return value
def setData(self, index, value, role):
return False
def rowCount(self, index):
return self.table_data.shape[0]
def columnCount(self, index):
return self.table_data.shape[1]
class CustomHeaderView(QHeaderView):
def __init__(self, orientation, parent=None):
super(CustomHeaderView, self).__init__(orientation, parent)
self.setSectionsClickable(True)
def mousePressEvent(self, event):
super().mousePressEvent(event)
class CustomProxyModel(QSortFilterProxyModel):
def __init__(self, parent=None):
super(CustomProxyModel, self).__init__(parent)
def sort(self, column, order):
return super().sort(column, order)
class SimpleGUI(QMainWindow):
def __init__(self):
super().__init__()
self.setWindowTitle("Simple PySide6 GUI")
self.setGeometry(100, 100, 800, 600)
# Create a QTreeView on the left
self.tree_view = QTreeView()
self.tree_view.setHeaderHidden(True)
self.tree_view.setRootIsDecorated(True)
# Create a QFileSystemModel to populate the QTreeView
self.treeView_model = QStandardItemModel(self)
self.tree_view.setModel(self.treeView_model)
self.init_treeView()
self.tree_view.clicked.connect(self.treeView_clicked)
# Create a QTableView on the right
self.table_view = QTableView()
self.tableView_model = CustomTableModel(parent=self)
# COMMENT THESE LINES FOR QSORTFILTERPROXY BYPASS
self.proxy_model = CustomProxyModel(self)
self.proxy_model.setSourceModel(self.tableView_model)
self.table_view.setModel(self.proxy_model)
# UNCOMMMENT FOR QSORTFILTERPROXY BYPASS
# self.table_view.setModel(self.tableView_model)
self.header_view = CustomHeaderView(Qt.Orientation.Horizontal, self)
self.table_view.setHorizontalHeader(self.header_view)
self.table_view.setSortingEnabled(True)
self.table_view_data_dict = {
"item1": ["1_1", "1_2", "1_3"],
"item2": ["2_1", "2_2", "2_3"],
"item3": ["3_1", "3_2", "3_3"],
}
# Create a vertical layout for the main window
main_layout = QHBoxLayout()
# Add the treeView to the layout
main_layout.addWidget(self.tree_view)
# Add the tableView to the layout
main_layout.addWidget(self.table_view)
# Create a central widget and set the main layout
central_widget = QWidget()
central_widget.setLayout(main_layout)
# Set the central widget for the main window
self.setCentralWidget(central_widget)
def init_treeView(self):
parent = self.treeView_model.invisibleRootItem()
data = [
"item1",
"item2",
"item3",
]
for element in data:
child = QStandardItem(element)
parent.appendRow(child)
def treeView_clicked(self, index):
self.clicked_treeView_item = self.treeView_model.itemFromIndex(index).text()
df_for_tableView = pd.DataFrame(self.table_view_data_dict[self.clicked_treeView_item]).T
self.tableView_model.table_data = df_for_tableView
self.tableView_model.layoutChanged.emit()
if __name__ == "__main__":
app = QApplication(sys.argv)
window = SimpleGUI()
window.show()
sys.exit(app.exec_())
Both bugs are reproducible:
-
click on item in treeView, click on cell in tableView, click on treeView again → crash (you’ll have to try a few times)
-
click on treeView, click on column header, click on cell, click on treeView, click on column header again → crash (you’ll have to try a few times)
Any suggestions?
Thank you in advance