我正在用Python 3.5开发一个使用PyQt5(5.7.1)的应用程序。我使用QTableView来显示一长串记录(超过10,000)。我希望能够在同一时间对多个列进行排序和过滤。PyQt - 如何重新实现QAbstractTableModel排序?
我尝试使用带有QSortFilterProxyModel一个QAbstractTableModel,重新实现QSortFilterProxyModel.filterAcceptsRow()具有多列过滤(见本博客文章:http://www.dayofthenewdan.com/2013/02/09/Qt_QSortFilterProxyModel.html)。但由于每行都调用此方法,因此在有大量行时过滤非常缓慢。
我以为使用熊猫进行过滤可以提高性能。所以,我创建了以下PandasTableModel类,它的确可以即使有大量的行非常快速地执行多列过滤,以及排序:
import pandas as pd
from PyQt5 import QtCore, QtWidgets
class PandasTableModel(QtCore.QAbstractTableModel):
def __init__(self, parent=None, *args):
super(PandasTableModel, self).__init__(parent, *args)
self._filters = {}
self._sortBy = []
self._sortDirection = []
self._dfSource = pd.DataFrame()
self._dfDisplay = pd.DataFrame()
def rowCount(self, parent=QtCore.QModelIndex()):
if parent.isValid():
return 0
return self._dfDisplay.shape[0]
def columnCount(self, parent=QtCore.QModelIndex()):
if parent.isValid():
return 0
return self._dfDisplay.shape[1]
def data(self, index, role):
if index.isValid() and role == QtCore.Qt.DisplayRole:
return QtCore.QVariant(self._dfDisplay.values[index.row()][index.column()])
return QtCore.QVariant()
def headerData(self, col, orientation=QtCore.Qt.Horizontal, role=QtCore.Qt.DisplayRole):
if orientation == QtCore.Qt.Horizontal and role == QtCore.Qt.DisplayRole:
return QtCore.QVariant(str(self._dfDisplay.columns[col]))
return QtCore.QVariant()
def setupModel(self, header, data):
self._dfSource = pd.DataFrame(data, columns=header)
self._sortBy = []
self._sortDirection = []
self.setFilters({})
def setFilters(self, filters):
self.modelAboutToBeReset.emit()
self._filters = filters
self.updateDisplay()
self.modelReset.emit()
def sort(self, col, order=QtCore.Qt.AscendingOrder):
#self.layoutAboutToBeChanged.emit()
column = self._dfDisplay.columns[col]
ascending = (order == QtCore.Qt.AscendingOrder)
if column in self._sortBy:
i = self._sortBy.index(column)
self._sortBy.pop(i)
self._sortDirection.pop(i)
self._sortBy.insert(0, column)
self._sortDirection.insert(0, ascending)
self.updateDisplay()
#self.layoutChanged.emit()
self.dataChanged.emit(QtCore.QModelIndex(), QtCore.QModelIndex())
def updateDisplay(self):
dfDisplay = self._dfSource.copy()
# Filtering
cond = pd.Series(True, index = dfDisplay.index)
for column, value in self._filters.items():
cond = cond & \
(dfDisplay[column].str.lower().str.find(str(value).lower()) >= 0)
dfDisplay = dfDisplay[cond]
# Sorting
if len(self._sortBy) != 0:
dfDisplay.sort_values(by=self._sortBy,
ascending=self._sortDirection,
inplace=True)
# Updating
self._dfDisplay = dfDisplay
该类复制一个QSortFilterProxyModel的行为,除了一个方面。如果在QTableView中选择了表格中的项目,排序表格将不会影响选择(例如,如果在排序之前选择了第一行,排序后仍然会选择第一行,与之前不同)
我认为这个问题与发出的信号有关,为了过滤,我使用了modelAboutToBeReset()和modelReset(),但是这些信号取消了QTableView中的选择,所以它们不适合排序。我在那里读到了( How to update QAbstractTableModel and QTableView after sorting the data source? )layoutAboutToBeChanged()和layoutChanged()应该被发射,但是,如果我使用这些信号,QTableView不会更新(我不明白为什么会这样),当排序完成后发射dataChanged()时,QTableView会被更新,但与上述行为(选择未更新)。class Ui_TableFilteringDialog(object):
def setupUi(self, TableFilteringDialog):
TableFilteringDialog.setObjectName("TableFilteringDialog")
TableFilteringDialog.resize(400, 300)
self.verticalLayout = QtWidgets.QVBoxLayout(TableFilteringDialog)
self.verticalLayout.setObjectName("verticalLayout")
self.tableView = QtWidgets.QTableView(TableFilteringDialog)
self.tableView.setObjectName("tableView")
self.tableView.setSortingEnabled(True)
self.tableView.setSelectionBehavior(QtWidgets.QAbstractItemView.SelectRows)
self.verticalLayout.addWidget(self.tableView)
self.groupBox = QtWidgets.QGroupBox(TableFilteringDialog)
self.groupBox.setObjectName("groupBox")
self.verticalLayout_2 = QtWidgets.QVBoxLayout(self.groupBox)
self.verticalLayout_2.setObjectName("verticalLayout_2")
self.formLayout = QtWidgets.QFormLayout()
self.formLayout.setObjectName("formLayout")
self.column1Label = QtWidgets.QLabel(self.groupBox)
self.column1Label.setObjectName("column1Label")
self.formLayout.setWidget(0, QtWidgets.QFormLayout.LabelRole, self.column1Label)
self.column1Field = QtWidgets.QLineEdit(self.groupBox)
self.column1Field.setObjectName("column1Field")
self.formLayout.setWidget(0, QtWidgets.QFormLayout.FieldRole, self.column1Field)
self.column2Label = QtWidgets.QLabel(self.groupBox)
self.column2Label.setObjectName("column2Label")
self.formLayout.setWidget(1, QtWidgets.QFormLayout.LabelRole, self.column2Label)
self.column2Field = QtWidgets.QLineEdit(self.groupBox)
self.column2Field.setObjectName("column2Field")
self.formLayout.setWidget(1, QtWidgets.QFormLayout.FieldRole, self.column2Field)
self.verticalLayout_2.addLayout(self.formLayout)
self.verticalLayout.addWidget(self.groupBox)
self.retranslateUi(TableFilteringDialog)
QtCore.QMetaObject.connectSlotsByName(TableFilteringDialog)
def retranslateUi(self, TableFilteringDialog):
_translate = QtCore.QCoreApplication.translate
TableFilteringDialog.setWindowTitle(_translate("TableFilteringDialog", "Dialog"))
self.groupBox.setTitle(_translate("TableFilteringDialog", "Filters"))
self.column1Label.setText(_translate("TableFilteringDialog", "Name"))
self.column2Label.setText(_translate("TableFilteringDialog", "Occupation"))
class TableFilteringDialog(QtWidgets.QDialog):
def __init__(self, parent=None):
super(TableFilteringDialog, self).__init__(parent)
self.ui = Ui_TableFilteringDialog()
self.ui.setupUi(self)
self.tableModel = PandasTableModel()
header = ['Name', 'Occupation']
data = [
['Abe', 'President'],
['Angela', 'Chancelor'],
['Donald', 'President'],
['François', 'President'],
['Jinping', 'President'],
['Justin', 'Prime minister'],
['Theresa', 'Prime minister'],
['Vladimir', 'President'],
['Donald', 'Duck']
]
self.tableModel.setupModel(header, data)
self.ui.tableView.setModel(self.tableModel)
self.ui.column1Field.textEdited.connect(self.filtersEdited)
self.ui.column2Field.textEdited.connect(self.filtersEdited)
def filtersEdited(self):
filters = {}
values = [
self.ui.column1Field.text().lower(),
self.ui.column2Field.text().lower()
]
for col, value in enumerate(values):
if value == '':
continue
column = self.tableModel.headerData(col, QtCore.Qt.Horizontal, QtCore.Qt.DisplayRole).value()
filters[column]=value
self.tableModel.setFilters(filters)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
dialog = TableFilteringDialog()
dialog.show()
sys.exit(app.exec_())
我怎样才能让排序时选择按照选定的元素:
可以使用下面的示例中测试这种模式?
您需要更新持久模型索引,视图使用这些索引来跟踪选定和扩展的项目。查看[QAbstractItemModel:Subclassing]的最后几段(https://doc.qt.io/qt-5/qabstractitemmodel.html#subclassing)。这没有简单的解决方案。 – ekhumoro
感谢您的提示,我找到了一个解决方案(见下文) –