如何使 QTableWidget 标题可编辑？

QTableWidget::setHorizo​​ntalHeaderItem(int column, QTableWidgetItem *item)

将列列的水平标题元素设置为项目。

QTableWidgetItem::setText(const QString &text)

将项目的文本设置为指定的文本。

from PyQt5.QtCore    import *
from PyQt5.QtGui     import *
from PyQt5.QtWidgets import *


class Dialog(QDialog):
    def __init__(self, parent=None):
        super(Dialog, self).__init__(parent)

        self.tableWidget = QTableWidget(2, 3)
        self.tableWidget.setHorizontalHeaderLabels(["A", "B", "C"])
        
        self.lineEdit_0 = QLineEdit()
        self.lineEdit_1 = QLineEdit()
        self.lineEdit_2 = QLineEdit()
        
        lay = QGridLayout(self)
        lay.addWidget(self.tableWidget, 0, 0, 1, 3)
        lay.addWidget(self.lineEdit_0, 1, 0)
        lay.addWidget(self.lineEdit_1, 1, 1)
        lay.addWidget(self.lineEdit_2, 1, 2)
        lay.addWidget(QPushButton("New Header 0", clicked=self.onClick), 2, 0)
        lay.addWidget(QPushButton("New Header 1", clicked=self.onClick), 2, 1)
        lay.addWidget(QPushButton("New Header 2", clicked=self.onClick), 2, 2)
        
    def onClick(self):
        sender = self.sender()
        if sender.text() == "New Header 0":
            title = QTableWidgetItem()                               # <---
            title.setText(self.lineEdit_0.text())                    # <---
            self.tableWidget.setHorizontalHeaderItem(0, title)       # <---       
        elif sender.text() == "New Header 1":
            item = QTableWidgetItem()
            item.setText(self.lineEdit_1.text())
            self.tableWidget.setHorizontalHeaderItem(1, item)  
        elif sender.text() == "New Header 2":
            item = QTableWidgetItem()
            item.setText(self.lineEdit_2.text())
            self.tableWidget.setHorizontalHeaderItem(2, item)  


if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    w = Dialog()
    w.resize(340, 200)
    w.exec_()

更新

我希望标题像单元格一样可编辑：双击并直接在标题中写入。

QHeaderView类为项目视图提供标题行或标题列。

from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore    import *
from PyQt5.QtGui     import *
from PyQt5.QtWidgets import *


class HeaderView(QtWidgets.QHeaderView):
    def __init__(self, parent):
        super(HeaderView, self).__init__(QtCore.Qt.Horizontal, parent)
        
        self.m_labels = []
        self.sectionResized.connect(self.adjustPositions)
        self.sectionCountChanged.connect(self.onSectionCountChanged)
        self.parent().horizontalScrollBar().valueChanged.connect(self.adjustPositions)

    @QtCore.pyqtSlot()
    def onSectionCountChanged(self):
        while self.m_labels:
            label = self.m_labels.pop()
            label.deleteLater()
        for i in range(self.count()):
            label = QtWidgets.QLineEdit(self) 
            label.setStyleSheet("QLineEdit { color: red; font-size: 12px; }")
            self.m_labels.append(label)
            self.update_data()
            self.adjustPositions()

    def setModel(self, model):
        super(HeaderView, self).setModel(model)
        if self.model() is not None:
            self.model().headerDataChanged.connect(self.update_data)

    def update_data(self):
        option = QtWidgets.QStyleOptionHeader()
        self.initStyleOption(option)
        for i, label in enumerate(self.m_labels):
            text = self.model().headerData(
                i, self.orientation(), QtCore.Qt.DisplayRole
            )
            label.setText(str(text))
            pal = label.palette()
            bc = self.model().headerData(
                i, self.orientation(), QtCore.Qt.BackgroundRole
            )
            if bc is None:
                bc = option.palette.brush(QtGui.QPalette.Window)
            pal.setBrush(QtGui.QPalette.Window, bc)

            fc = self.model().headerData(
                i, self.orientation(), QtCore.Qt.ForegroundRole
            )
            if fc is None:
                fc = option.palette.brush(QtGui.QPalette.ButtonText)
            pal.setBrush(QtGui.QPalette.ButtonText, fc)

            label.setPalette(pal)

            textAlignment = self.model().headerData(
                i, self.orientation(), QtCore.Qt.TextAlignmentRole
            )
            if textAlignment is None:
                textAlignment = self.defaultAlignment()
            label.setAlignment(textAlignment)

    def updateGeometries(self):
        super(HeaderView, self).updateGeometries()
        self.adjustPositions()

    @QtCore.pyqtSlot()
    def adjustPositions(self):
        for index, label in enumerate(self.m_labels):
            geom = QtCore.QRect(
                self.sectionViewportPosition(index),
                0,
                self.sectionSize(index),
                self.height(),
            )
            geom.adjust(2, 0, -2, 0)
            label.setGeometry(geom)

class Dialog(QDialog):
    def __init__(self, parent=None):
        super(Dialog, self).__init__(parent)

        self.tableWidget = QTableWidget(2, 3)
       
        header = HeaderView(self.tableWidget)
        self.tableWidget.setHorizontalHeader(header)
        
        header_labels = []
        for i in range(self.tableWidget.columnCount()):
            header_label = "Column-{}".format(i)
            header_labels.append(header_label)
        self.tableWidget.setHorizontalHeaderLabels(header_labels)        
        
        lay = QGridLayout(self)
        lay.addWidget(self.tableWidget) 


if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    w = Dialog()
    w.resize(340, 150)
    w.exec_()