PyQT QTableWidget 非常慢 [英] PyQT QTableWidget extremely slow

问题描述

这是我用来填充在 QT Designer 中绘制的表格的代码.设计为适用于任何桌子，它工作正常，但是......当我尝试显示包含 18 列和 ~12000 行的 datasat 时，它只会冻结 30 秒或更长时间.那么，我做错了什么，有没有办法加快速度，使代码仍然适用于任何表?

this is the code I use to fill a table drawn in QT Designer. Designed to be universal for any table, it works fine, but... When I try to show a datasat containing 18 columns and ~12000 rows, it just freezes for 30 seconds or more. So, what I am doing wrong and is there way to speed up, keeping the code still suitable for any table?

这是我的代码:

...blablabla...

self.connect(self, SIGNAL("set"), self.real_set)

...blablabla...

def set_table(self, table, data):
    self.emit(SIGNAL('set'), table, data)

def real_set(self, table, data):
    """
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    Assuming data is list of dict and table is a QTableWidget.

    Get first key and get len of contents
    """
    for key in data:
        rows = len(data[key])
        table.setRowCount(rows)
        break

    """
    Forbid resizing(speeds up)
    """
    table.horizontalHeader().setResizeMode(QHeaderView.Fixed)
    table.verticalHeader().setResizeMode(QHeaderView.Fixed)
    table.horizontalHeader().setStretchLastSection(False)
    table.verticalHeader().setStretchLastSection(False)

    """
    Set number of columns too
    """
    table.setColumnCount(len(data))
    table.setHorizontalHeaderLabels(sorted(data.keys()))

    """
    Now fill data
    """
    for n, key in enumerate(sorted(data.keys())):
        for m, item in enumerate(data[key]):
            newitem = QTableWidgetItem(item)
            table.setItem(m, n, newitem)

推荐答案

这里是一个测试脚本，它比较了几种填充表格的方法.

Here a test script which compares a few ways of populating a table.

自定义模型要快得多，因为它不必预先创建所有项目——但请注意，它是一个非常基本的实现，因此没有实现排序、编辑等.(参见 模型/视图编程 了解更多详情).

The custom model is much faster, because it does not have to create all the items up front - but note that it is a very basic implementation, so does not implement sorting, editing, etc. (See Model/View Programming for more details).

from random import shuffle
from PyQt4 import QtCore, QtGui

class TableModel(QtCore.QAbstractTableModel):
    def __init__(self, data, parent=None):
        super(TableModel, self).__init__(parent)
        self._data = data

    def rowCount(self, parent=None):
        return len(self._data)

    def columnCount(self, parent=None):
        return len(self._data[0]) if self.rowCount() else 0

    def data(self, index, role=QtCore.Qt.DisplayRole):
        if role == QtCore.Qt.DisplayRole:
            row = index.row()
            if 0 <= row < self.rowCount():
                column = index.column()
                if 0 <= column < self.columnCount():
                    return self._data[row][column]

class Window(QtGui.QWidget):
    def __init__(self):
        super(Window, self).__init__()
        self.table = QtGui.QTableView(self)
        self.tablewidget = QtGui.QTableWidget(self)
        self.tablewidget.setSortingEnabled(True)
        self.button1 = QtGui.QPushButton('Custom Model', self)
        self.button1.clicked.connect(
            lambda: self.populateTable('custom'))
        self.button2 = QtGui.QPushButton('StandardItem Model', self)
        self.button2.clicked.connect(
            lambda: self.populateTable('standard'))
        self.button3 = QtGui.QPushButton('TableWidget', self)
        self.button3.clicked.connect(
            lambda: self.populateTable('widget'))
        self.spinbox = QtGui.QSpinBox(self)
        self.spinbox.setRange(15000, 1000000)
        self.spinbox.setSingleStep(10000)
        layout = QtGui.QGridLayout(self)
        layout.addWidget(self.table, 0, 0, 1, 4)
        layout.addWidget(self.tablewidget, 1, 0, 1, 4)
        layout.addWidget(self.button1, 2, 0)
        layout.addWidget(self.button2, 2, 1)
        layout.addWidget(self.button3, 2, 2)
        layout.addWidget(self.spinbox, 2, 3)
        self._data = []

    def populateTable(self, mode):
        if mode == 'widget':
            self.tablewidget.clear()
            self.tablewidget.setRowCount(self.spinbox.value())
            self.tablewidget.setColumnCount(20)
        else:
            model = self.table.model()
            if model is not None:
                self.table.setModel(None)
                model.deleteLater()
        if len(self._data) != self.spinbox.value():
            del self._data[:]
            rows = list(range(self.spinbox.value()))
            shuffle(rows)
            for row in rows:
                items = []
                for column in range(20):
                    items.append('(%d, %d)' % (row, column))
                self._data.append(items)
        timer = QtCore.QElapsedTimer()
        timer.start()
        if mode == 'widget':
            self.tablewidget.setSortingEnabled(False)
            for row, items in enumerate(self._data):
                for column, text in enumerate(items):
                    item = QtGui.QTableWidgetItem(text)
                    self.tablewidget.setItem(row, column, item)
            self.tablewidget.sortByColumn(0, QtCore.Qt.AscendingOrder)
        else:
            self.table.setSortingEnabled(False)
            if mode == 'custom':
                model = TableModel(self._data, self.table)
            elif mode == 'standard':
                model = QtGui.QStandardItemModel(self.table)
                for row in self._data:
                    items = []
                    for column in row:
                        items.append(QtGui.QStandardItem(column))
                    model.appendRow(items)
            self.table.setModel(model)
            self.table.setSortingEnabled(True)
            self.table.sortByColumn(0, QtCore.Qt.AscendingOrder)
        print('%s: %.3g seconds' % (mode, timer.elapsed() / 1000))

if __name__ == '__main__':

    import sys
    app = QtGui.QApplication(sys.argv)
    window = Window()
    window.setGeometry(600, 50, 1200, 800)
    window.show()
    sys.exit(app.exec_())

这篇关于PyQT QTableWidget 非常慢的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！