Hi, I have a table with two columns and approx. 50.000 rows of data. When I use the QSortFilterProxyModel, sorting is painfully slow.
I implemented a test model with one column and 500.000 string entries. When sorting with QSortFilterProxyModel, it takes approx. 5 seconds on my computer to sort. Using the builtin sort functions in Python it sorts instantly.
Is there any way to speed up the QSortFilterProxyModel? Or do I need to implement a custom sort method in all my models?

The test model looks like this, I hope it is correctly implemented, at least the correct index is returned when clicking on a row after sorting ;-)

Qt Code: 
  1. import sys
  2.  
  3. from PyQt5.QtCore import *
  4. from PyQt5.QtGui import *
  5. from PyQt5.QtWidgets import *
  6.  
  7.  
  8. class MyModel(QAbstractTableModel):
  9.  
  10.     def __init__(self, parent=None):
  11.         super().__init__(parent)
  12.         self._data = [str(i).rjust(6, '0') for i in range(500_000)]
  13.  
  14.     def data(self, index: QModelIndex, role=None):
  15.         if not index or not index.isValid():
  16.             return QVariant()
  17.         if index.column() == 0 and role == Qt.DisplayRole:
  18.             return self._data[index.row()]
  19.         return QVariant()
  20.  
  21.     def rowCount(self, parent=None, *args, **kwargs):
  22.         return len(self._data)
  23.  
  24.     def columnCount(self, parent=None, *args, **kwargs):
  25.         return 1
  26.  
  27.     def headerData(self, column, orientation, role=None):
  28.         if role == Qt.DisplayRole and orientation == Qt.Horizontal and column == 0:
  29.             return 'Values'
  30.         return QVariant()
  31.  
  32.     def sort(self, column, order=None):
  33.         self.layoutAboutToBeChanged.emit()
  34.         if order == Qt.AscendingOrder:
  35.             self._data.sort()
  36.         else:
  37.             self._data.sort(reverse=True)
  38.         self.layoutChanged.emit()
  39.         self.dataChanged.emit(QModelIndex(), QModelIndex())
  40.  
  41.  
  42. if __name__ == "__main__":
  43.     app = QApplication(sys.argv)
  44.  
  45.     view = QTableView()
  46.     model = MyModel(view)
  47.     view.setModel(model)
  48.     view.resizeColumnsToContents()
  49.     view.horizontalHeader().setStretchLastSection(True)
  50.     view.setSortingEnabled(True)
  51.     view.sortByColumn(0, Qt.AscendingOrder)
  52.     view.show()
  53.  
  54.     sys.exit(app.exec_())
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But I wonder if it is possible to speed up the builtin Qt models, maybe there is a flag I'm not aware of?
Sorting 50.000 entries (or in this example 500.000 entries) should take that long?