How to add search bar in column filter in QTableWidget in Pyqt5 Python?

Question

I have a created a QTableWidget using pyqt5 and managed to add filter option in each column of the table widget successfully with one of the answers available on stack overflow. filters works as expected but I wanted to add search bar in the filter at the top to search for the values.

In my actual Script I would probably have around 3-4k unique values in filter so it becomes easy if there's a way to search for a value in the filter.

Also, Is there a way we can add scroll bar in this because currently if I add more values to the table, my filter area gets bigger and bigger to accumulate all values.

I am posting minimal working code below.

Code Generated by UIDesigner:

from PyQt5 import QtCore, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(800, 600)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.tableWidget = QtWidgets.QTableWidget(self.centralwidget)
        self.tableWidget.setGeometry(QtCore.QRect(10, 10, 771, 561))
        self.tableWidget.setObjectName("tableWidget")
        self.tableWidget.setColumnCount(0)
        self.tableWidget.setRowCount(0)
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

My Script:

from PyQt5 import QtWidgets, QtCore
from PyQt5.QtWidgets import QTableWidgetItem
import pandas as pd

from demo import Ui_MainWindow

class DemoTable(QtWidgets.QMainWindow, Ui_MainWindow):  
    #signalrunningriskmanagertext = QtCore.pyqtSignal(str)

    def __init__(self):
        super(DemoTable, self).__init__()
        self.setupUi(self) 

        #Set up table data
        self.tableWidget.setRowCount(25)
        self.tableWidget.setColumnCount(4)

        self.tableWidget.setHorizontalHeaderLabels(['A','B','C','D'])
        d = {'A': range(0,25), 
             'B': range(20,45),
             'C': ['a','b','c','d','e','f','g','h','i','d','s','n','s','t','h','d','t','s','t','s','e','y','d','b','s'],
             'D': ['a','b','c','d','e','f','g','h','i','d','s','n','s','t','h','d','t','s','t','s','e','y','d','b','s']}
        df = pd.DataFrame(data=d)

        for row in range(0,25):
            for column in range(0,4):
                item = QTableWidgetItem(str(df.iloc[row,column]))
                self.tableWidget.setItem(row, column, item)

        #Add filters in column
        self.tableWidgetHeader = self.tableWidget.horizontalHeader()
        self.tableWidgetHeader.sectionClicked.connect(self.columnfilterclicked)
        self.keywords = dict([(i, []) for i in range(self.tableWidget.columnCount())])
        self.checkBoxs = []
        self.col = None

    def slotSelect(self, state):
        for checkbox in self.checkBoxs:
            checkbox.setChecked(QtCore.Qt.Checked == state)

    def menuClose(self):
        self.keywords[self.col] = []
        for element in self.checkBoxs:
            if element.isChecked():
                self.keywords[self.col].append(element.text())
        self.filterdata()
        self.menu.close()

    def clearFilter(self):
        if self.tableWidget.rowCount() > 0:
            for i in range(self.tableWidget.rowCount()):
                self.tableWidget.setRowHidden(i, False)

    def filterdata(self):
        columnsShow = dict([(i, True) for i in range(self.tableWidget.rowCount())])

        for i in range(self.tableWidget.rowCount()):
            for j in range(self.tableWidget.columnCount()):
                item = self.tableWidget.item(i, j)
                if self.keywords[j]:
                    if item.text() not in self.keywords[j]:
                        columnsShow[i] = False
        for key in columnsShow:
            self.tableWidget.setRowHidden(key, not columnsShow[key])

    def columnfilterclicked(self,index):
        self.menu = QtWidgets.QMenu(self)
        self.col = index

        data_unique = []

        self.checkBoxs = []

        checkBox = QtWidgets.QCheckBox("Select all", self.menu)
        checkableAction = QtWidgets.QWidgetAction(self.menu)
        checkableAction.setDefaultWidget(checkBox)
        self.menu.addAction(checkableAction)
        checkBox.setChecked(True)
        checkBox.stateChanged.connect(self.slotSelect)

        for i in range(self.tableWidget.rowCount()):
            if not self.tableWidget.isRowHidden(i):
                item = self.tableWidget.item(i, index)
                if item.text() not in data_unique:
                    data_unique.append(item.text())
                    checkBox = QtWidgets.QCheckBox(item.text(), self.menu)
                    checkBox.setChecked(True)
                    checkableAction = QtWidgets.QWidgetAction(self.menu)
                    checkableAction.setDefaultWidget(checkBox)
                    self.menu.addAction(checkableAction)
                    self.checkBoxs.append(checkBox)

        btn = QtWidgets.QDialogButtonBox(QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel,
                                     QtCore.Qt.Horizontal, self.menu)
        btn.accepted.connect(self.menuClose)
        btn.rejected.connect(self.menu.close)
        checkableAction = QtWidgets.QWidgetAction(self.menu)
        checkableAction.setDefaultWidget(btn)
        self.menu.addAction(checkableAction)

        headerPos = self.tableWidget.mapToGlobal(self.tableWidgetHeader.pos())

        posY = headerPos.y() + self.tableWidgetHeader.height()
        posX = headerPos.x() + self.tableWidgetHeader.sectionPosition(index)
        self.menu.exec_(QtCore.QPoint(posX, posY))

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    window = DemoTable()
    window.show()
    sys.exit(app.exec_())