通过QSqlRelationalTableMod中的QSortFilterProxyModel进行过滤时，QTreeView上会出现无休止的循环

Question

每当我用QSortFilterProxyModel()启用一个过滤器并在我的QSqlRelationalTableModel()中插入一个链接到QTreeView的新记录时，我都会得到错误：

RecursionError: maximum recursion depth exceeded

标准情况是创建一个CTRL + N-OK的新数据记录。你知道吗

也可以过滤-好的。你知道吗

但是如果我设置了过滤器并创建了一个新记录，python就会失败：

RecursionError: maximum recursion depth exceeded
Backend terminated (returncode: 3)
Fatal Python error: Aborted

如何复制：

1. 设置一个过滤器，例如lastName到Smith。你知道吗
2. 点击CTRL + N创建新记录。你知道吗

=>；结果：Python陷入无休止的循环中，直到出现上述错误消息。你知道吗

=>；预期结果：应创建行，而不是被筛选器命中。删除过滤器时，应显示所有行，以及新创建的行。你知道吗

完整工作代码示例：

import sys
import re
from PyQt5 import QtWidgets, QtGui, QtCore, QtSql

db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
db.setDatabaseName(":memory:");
modelQuery = QtSql.QSqlQueryModel()
modelTable = QtSql.QSqlRelationalTableModel()

def _human_key(key):
    parts = re.split(r'(\d*\.\d+|\d+)', key)
    return tuple((e.swapcase() if i % 2 == 0 else float(e))
            for i, e in enumerate(parts))

class FilterHeader(QtWidgets.QHeaderView):
    filterActivated = QtCore.pyqtSignal()

    def __init__(self, parent):
        super().__init__(QtCore.Qt.Horizontal, parent)
        self._editors = []
        self._padding = 4
        self.setStretchLastSection(True)        
        self.setDefaultAlignment(QtCore.Qt.AlignLeft | QtCore.Qt.AlignVCenter)
        self.setSortIndicatorShown(False)
        self.sectionResized.connect(self.adjustPositions)
        parent.horizontalScrollBar().valueChanged.connect(self.adjustPositions)

    def setFilterBoxes(self, count):
        while self._editors:
            editor = self._editors.pop()
            editor.deleteLater()
        for index in range(count):
            editor = QtWidgets.QLineEdit(self.parent())            
            editor.setPlaceholderText('Filter')
            editor.setClearButtonEnabled(True)            
            editor.textChanged.connect(self.textChanged)

            self._editors.append(editor)
        self.adjustPositions()

    def textChanged(self):        
        self.filterActivated.emit()

    def sizeHint(self):
        size = super().sizeHint()
        if self._editors:
            height = self._editors[0].sizeHint().height()
            size.setHeight(size.height() + height + self._padding)
        return size

    def updateGeometries(self):
        if self._editors:
            height = self._editors[0].sizeHint().height()
            self.setViewportMargins(0, 0, 0, height + self._padding)
        else:
            self.setViewportMargins(0, 0, 0, 0)
        super().updateGeometries()
        self.adjustPositions()

    def adjustPositions(self):
        for index, editor in enumerate(self._editors):
            height = editor.sizeHint().height()
            editor.move(
                self.sectionPosition(index) - self.offset() + 2,
                height + (self._padding // 2))
            editor.resize(self.sectionSize(index), height)

    def filterText(self, index):        
        if 0 <= index < len(self._editors):
            return self._editors[index].text()
        return ''

    def setFilterText(self, index, text):
        if 0 <= index < len(self._editors):
            self._editors[index].setText(text)

    def clearFilters(self):        
        for editor in self._editors:
            editor.clear()


class HumanProxyModel(QtCore.QSortFilterProxyModel):
    def lessThan(self, source_left, source_right):
        data_left = source_left.data()
        data_right = source_right.data()
        if type(data_left) == type(data_right) == str:
            return _human_key(data_left) < _human_key(data_right)
        return super(HumanProxyModel, self).lessThan(source_left, source_right)

    @property
    def filters(self):        
        if not hasattr(self, "_filters"):
            self._filters = []        
        return self._filters

    @filters.setter
    def filters(self, filters):
        self._filters = filters
        self.invalidateFilter()

    def filterAcceptsRow(self, sourceRow, sourceParent):            
        for i, text in self.filters:
            if 0 <= i < self.columnCount():            
                ix = self.sourceModel().index(sourceRow, i, sourceParent)
                data = ix.data()
                if text not in data:                    
                    return False        
        return True                

class winMain(QtWidgets.QMainWindow):
    cur_row = -1
    row_id = -1

    def __init__(self, parent=None):        
        super().__init__(parent)                
        self.setupUi()
        self.setGeometry(300,200,700,500)

        self.treeView.selectionModel().selectionChanged.connect(self.item_selection_changed_slot)        
        self.center()
        self.show()                

    def new_dataset(self):
        print("new_dataset() called.")            

        # get new row
        row = modelTable.rowCount()
        new_row = row+1
        self.cur_row = new_row        

        # get next free row id
        model = QtSql.QSqlQueryModel()
        model.setQuery("SELECT max(id)+1 FROM person")
        self.row_id = model.data(model.index(0, 0))        

        # insert a new row with dummy data
        modelTable.insertRow(row)
        modelTable.setData(modelTable.index(row,0), self.row_id, QtCore.Qt.EditRole)
        modelTable.setData(modelTable.index(row,1), "new" + str(self.row_id), QtCore.Qt.EditRole)
        modelTable.setData(modelTable.index(row,2), "new" + str(self.row_id), QtCore.Qt.EditRole)
        modelTable.setData(modelTable.index(row,3), "new" + str(self.row_id), QtCore.Qt.EditRole)
        modelTable.setData(modelTable.index(row,4), 2, QtCore.Qt.EditRole)

        modelTable.submitAll()        

    def handleFilterActivated(self):        
        header = self.treeView.header()
        filters = []
        for i in range(header.count()):
            text = header.filterText(i)
            if text:
                filters.append((i, text))
        proxy = self.treeView.model()        
        proxy.filters = filters

    QtCore.pyqtSlot()
    def item_selection_changed_slot(self):
        selected = self.treeView.selectionModel()
        indexes = selected.selectedIndexes()        

        sourceIdx = self.treeView.currentIndex()
        ix = self.treeView.model().index(sourceIdx.row(), 0)  # column which contains the id

        self.cur_row = sourceIdx.row()
        self.row_id = ix.data()

        record = modelTable.record(self.cur_row)

        persId = record.value("persId")
        lastName = record.value("lastName")
        firstName = record.value("firstName")
        country = record.value("name")
        print(f"{persId} - {lastName}, {firstName} from {country} selected.")

    def keyReleaseEvent(self, eventQKeyEvent):                
        key = eventQKeyEvent.key()
        modifiers = QtWidgets.QApplication.keyboardModifiers()
        if modifiers == QtCore.Qt.ShiftModifier and key == QtCore.Qt.Key_Escape:            
                self.clear_all_filters()


    def center(self):
        frameGm = self.frameGeometry()
        screen = QtWidgets.QApplication.desktop().screenNumber(QtWidgets.QApplication.desktop().cursor().pos())
        centerPoint = QtWidgets.QApplication.desktop().screenGeometry(screen).center()
        frameGm.moveCenter(centerPoint)
        self.move(frameGm.topLeft())

    def setupUi(self):
        self.centralwidget = QtWidgets.QWidget(self)
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.centralwidget)

        self.treeView = QtWidgets.QTreeView(self.centralwidget)      

        self.treeView.setRootIsDecorated(False)                      
        self.treeView.setSortingEnabled(True)
        self.treeView.setAlternatingRowColors(True)        
        self.treeView.setEditTriggers(QtWidgets.QAbstractItemView.NoEditTriggers)
        self.treeView.setSelectionMode(QtWidgets.QAbstractItemView.ExtendedSelection)
        self.treeView.header().setStretchLastSection(True)           

        self.horizontalLayout.addWidget(self.treeView)
        self.setCentralWidget(self.centralwidget)

        header = FilterHeader(self.treeView)        
        self.treeView.setHeader(header)         

        # ToolBar        
        newDatasetAct = QtWidgets.QAction(QtGui.QIcon('img/icons8-new-file-50.png'), 'New dataset (CTRL+N)', self)
        newDatasetAct.setShortcut('Ctrl+N')
        newDatasetAct.triggered.connect(self.new_dataset)

        self.toolbar = self.addToolBar('Main')        
        self.toolbar.addAction(newDatasetAct)

        modelTable.setTable("person")

        modelTable.setRelation(4, QtSql.QSqlRelation("country", "id", "name"));

        modelTable.setEditStrategy(QtSql.QSqlTableModel.OnManualSubmit)

        self.treeView.setModel(modelTable) # display data of the SQLTableModel into the QTreeView      

        # enable human sorting                
        proxy = HumanProxyModel(self)
        proxy.setSourceModel(modelTable)
        self.treeView.setModel(proxy)

        # enable filtering
        header.setFilterBoxes(modelTable.columnCount())
        header.filterActivated.connect(self.handleFilterActivated)        

def create_sample_data():     
    modelQuery.setQuery("""CREATE TABLE IF NOT EXISTS country (                                    
                                    id   INTEGER PRIMARY KEY UNIQUE NOT NULL,
                                    name TEXT
                                    )""")

    # id         INTEGER PRIMARY KEY UNIQUE,
    modelQuery.setQuery("""CREATE TABLE IF NOT EXISTS person (
                                   id         INTEGER PRIMARY KEY UNIQUE NOT NULL,
                                   persId     TEXT,
                                   lastName   TEXT,
                                   firstName  TEXT,
                                   country_id INTEGER NOT NULL DEFAULT 3,
              FOREIGN KEY (country_id) REFERENCES country(id)
                                   )""")

    # create some sample data for our model
    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (0, 'None')")    
    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (1, 'Angola')")    
    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (2, 'Serbia')")
    modelQuery.setQuery("INSERT INTO country (id, name) VALUES (3, 'Georgia')")

    modelQuery.setQuery("INSERT INTO person (id, persId, lastName, firstName, country_id) VALUES (1, '1001', 'Martin', 'Robert', 1)")
    modelQuery.setQuery("INSERT INTO person (id, persId, lastName, firstName, country_id) VALUES (2, '1002', 'Smith', 'Brad', 2)")
    modelQuery.setQuery("INSERT INTO person (id, persId, lastName, firstName, country_id) VALUES (3, '1003', 'Smith', 'Angelina', 3)")

if __name__ == '__main__':                         
    app = QtWidgets.QApplication(sys.argv)             

    create_sample_data()

    window = winMain()    
    sys.exit(app.exec_())    

Answer 1

问题来自于对filterAcceptsRow中self.columnCount()的调用。^一个QSortFilterProxyModel的{}需要一个当前代理模型的映射，而当前代理模型又会再次调用filteraceptsrow，从而使函数递归。你知道吗

使用if 0 <= i < self.sourceModel().columnCount()问题就解决了。你知道吗