Python 如何使用SQL数据库更改QCalendarWidget中单元格的背景颜色

这不是重复的问题

这是那个问题的补充

这也不是的副本，因为这只是在用户在实际QT页面上选择单元格时高亮显示单元格，而不是使用SQL数据。这也不是一个重复的问题，因为答案不符合我希望我的程序的要求，即使用我的sql数据库更改日历中特定单元格的背景颜色，而且我无法得到有效的答案

在第一个链接问题中，我问用户如何按下日期，如果该日期在sql数据库中，它将输出与该日期对应的文本。在一些人的帮助下，我成功地使它工作起来。现在我要做的是用蓝色背景突出显示那些日期，就像当前日期用红色背景突出显示一样

我制作的QT页面如下：

        # -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'Calendar.ui'
#
# Created by: PyQt5 UI code generator 5.14.1
#
# WARNING! All changes made in this file will be lost!


from PyQt5 import QtCore, QtGui, QtWidgets
import sqlite3
import datetime
import PyQt5
from PyQt5.QtCore import QDate, Qt
from PyQt5.QtGui import (QColor, QFont, QTextCharFormat, QTextLength,
        QTextTableFormat)
from PyQt5.QtWidgets import (QApplication, QComboBox, QDateTimeEdit,
        QHBoxLayout, QLabel, QMainWindow, QSpinBox, QTextBrowser, QVBoxLayout,
        QWidget)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(1200, 900)
        MainWindow.setMinimumSize(QtCore.QSize(0, 0))
        MainWindow.setMaximumSize(QtCore.QSize(1200, 900))
        MainWindow.setStyleSheet("background-color: rgb(200, 200, 200);")
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.Header = QtWidgets.QTextEdit(self.centralwidget)
        self.Header.setEnabled(False)
        self.Header.setGeometry(QtCore.QRect(-10, 0, 1300, 110))
        self.Header.setMinimumSize(QtCore.QSize(1300, 110))
        self.Header.setMaximumSize(QtCore.QSize(1300, 110))
        self.Header.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(255, 255, 255);\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.Header.setObjectName("Header")
        self.LECTURP = QtWidgets.QLabel(self.centralwidget)
        self.LECTURP.setGeometry(QtCore.QRect(512, 2, 180, 61))
        self.LECTURP.setStyleSheet("color: rgb(0, 176, 240);\n"
"font: 8pt \"MS Shell Dlg 2\";\n"
"text-decoration: underline;\n"
"background-color: rgb(255, 255, 255);\n"
"font: 28pt \"Calbri\";\n"
"text-decoration: underline;")
        self.LECTURP.setObjectName("LECTURP")
        self.LecturpBanner = QtWidgets.QLabel(self.centralwidget)
        self.LecturpBanner.setGeometry(QtCore.QRect(320, 60, 561, 31))
        self.LecturpBanner.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"color: rgb(0, 176, 240);\n"
"font: 14pt \"Calibri\";")
        self.LecturpBanner.setObjectName("LecturpBanner")
        self.calendarWidget = QtWidgets.QCalendarWidget(self.centralwidget)
        self.calendarWidget.setGeometry(QtCore.QRect(30, 110, 1141, 661))
        self.calendarWidget.setStyleSheet("alternate-background-color: rgb(255, 255, 255);\n"
"font: 75 16pt \"MS Shell Dlg 2\";\n"
"background-color: rgb(200, 200, 200);\n"
"selection-background-color: rgb(255, 0, 0);")
        self.calendarWidget.setObjectName("calendarWidget")
        self.DateInfoOutput = QtWidgets.QLabel(self.centralwidget)
        self.DateInfoOutput.setGeometry(QtCore.QRect(30, 778, 1141, 97))
        self.DateInfoOutput.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(0, 0, 0);\n"
"font: 16pt \"Calibri\";\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.DateInfoOutput.setText("")
        self.DateInfoOutput.setObjectName("DateInfoOutput")
        self.WeekNumber = QtWidgets.QLabel(self.centralwidget)
        self.WeekNumber.setGeometry(QtCore.QRect(56, 168, 113, 49))
        self.WeekNumber.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"font: 16pt \"MS Shell Dlg 2\";")
        self.WeekNumber.setObjectName("WeekNumber")
        self.calendarWidget.raise_()
        self.Header.raise_()
        self.LECTURP.raise_()
        self.LecturpBanner.raise_()
        self.DateInfoOutput.raise_()
        self.WeekNumber.raise_()
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

        self.editor = QTextBrowser()


        self.calendarWidget.clicked[QDate].connect(self.dateClicked)


    def dateClicked(self, clickedDate):
        connection = sqlite3.connect("Calendardatabase.db") 
        crsr = connection.cursor() 
        crsr.execute(
            'SELECT Text FROM Calendar WHERE Day = ? AND Month = ? AND YEAR = ?', 
            (clickedDate.day(), clickedDate.month(), clickedDate.year()))
        result = crsr.fetchone()

        if result:
            self.DateInfoOutput.setText(result[0])
        else:
            self.DateInfoOutput.setText('')


    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.LECTURP.setText(_translate("MainWindow", "LECTURP"))
        self.LecturpBanner.setText(_translate("MainWindow", "Lecture, Exam, Coursework, Timetable, Uploader and Reminder Program."))
        self.WeekNumber.setText(_translate("MainWindow", "Week No."))


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_())

我的数据库是：

        # -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'Calendar.ui'
#
# Created by: PyQt5 UI code generator 5.14.1
#
# WARNING! All changes made in this file will be lost!


from PyQt5 import QtCore, QtGui, QtWidgets
import sqlite3
import datetime
import PyQt5
from PyQt5.QtCore import QDate, Qt
from PyQt5.QtGui import (QColor, QFont, QTextCharFormat, QTextLength,
        QTextTableFormat)
from PyQt5.QtWidgets import (QApplication, QComboBox, QDateTimeEdit,
        QHBoxLayout, QLabel, QMainWindow, QSpinBox, QTextBrowser, QVBoxLayout,
        QWidget)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(1200, 900)
        MainWindow.setMinimumSize(QtCore.QSize(0, 0))
        MainWindow.setMaximumSize(QtCore.QSize(1200, 900))
        MainWindow.setStyleSheet("background-color: rgb(200, 200, 200);")
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.Header = QtWidgets.QTextEdit(self.centralwidget)
        self.Header.setEnabled(False)
        self.Header.setGeometry(QtCore.QRect(-10, 0, 1300, 110))
        self.Header.setMinimumSize(QtCore.QSize(1300, 110))
        self.Header.setMaximumSize(QtCore.QSize(1300, 110))
        self.Header.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(255, 255, 255);\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.Header.setObjectName("Header")
        self.LECTURP = QtWidgets.QLabel(self.centralwidget)
        self.LECTURP.setGeometry(QtCore.QRect(512, 2, 180, 61))
        self.LECTURP.setStyleSheet("color: rgb(0, 176, 240);\n"
"font: 8pt \"MS Shell Dlg 2\";\n"
"text-decoration: underline;\n"
"background-color: rgb(255, 255, 255);\n"
"font: 28pt \"Calbri\";\n"
"text-decoration: underline;")
        self.LECTURP.setObjectName("LECTURP")
        self.LecturpBanner = QtWidgets.QLabel(self.centralwidget)
        self.LecturpBanner.setGeometry(QtCore.QRect(320, 60, 561, 31))
        self.LecturpBanner.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"color: rgb(0, 176, 240);\n"
"font: 14pt \"Calibri\";")
        self.LecturpBanner.setObjectName("LecturpBanner")
        self.calendarWidget = QtWidgets.QCalendarWidget(self.centralwidget)
        self.calendarWidget.setGeometry(QtCore.QRect(30, 110, 1141, 661))
        self.calendarWidget.setStyleSheet("alternate-background-color: rgb(255, 255, 255);\n"
"font: 75 16pt \"MS Shell Dlg 2\";\n"
"background-color: rgb(200, 200, 200);\n"
"selection-background-color: rgb(255, 0, 0);")
        self.calendarWidget.setObjectName("calendarWidget")
        self.DateInfoOutput = QtWidgets.QLabel(self.centralwidget)
        self.DateInfoOutput.setGeometry(QtCore.QRect(30, 778, 1141, 97))
        self.DateInfoOutput.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(0, 0, 0);\n"
"font: 16pt \"Calibri\";\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.DateInfoOutput.setText("")
        self.DateInfoOutput.setObjectName("DateInfoOutput")
        self.WeekNumber = QtWidgets.QLabel(self.centralwidget)
        self.WeekNumber.setGeometry(QtCore.QRect(56, 168, 113, 49))
        self.WeekNumber.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"font: 16pt \"MS Shell Dlg 2\";")
        self.WeekNumber.setObjectName("WeekNumber")
        self.calendarWidget.raise_()
        self.Header.raise_()
        self.LECTURP.raise_()
        self.LecturpBanner.raise_()
        self.DateInfoOutput.raise_()
        self.WeekNumber.raise_()
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

        self.editor = QTextBrowser()


        self.calendarWidget.clicked[QDate].connect(self.dateClicked)


    def dateClicked(self, clickedDate):
        connection = sqlite3.connect("Calendardatabase.db") 
        crsr = connection.cursor() 
        crsr.execute(
            'SELECT Text FROM Calendar WHERE Day = ? AND Month = ? AND YEAR = ?', 
            (clickedDate.day(), clickedDate.month(), clickedDate.year()))
        result = crsr.fetchone()

        if result:
            self.DateInfoOutput.setText(result[0])
        else:
            self.DateInfoOutput.setText('')


    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.LECTURP.setText(_translate("MainWindow", "LECTURP"))
        self.LecturpBanner.setText(_translate("MainWindow", "Lecture, Exam, Coursework, Timetable, Uploader and Reminder Program."))
        self.WeekNumber.setText(_translate("MainWindow", "Week No."))


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_())

我的代码是：

        # -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'Calendar.ui'
#
# Created by: PyQt5 UI code generator 5.14.1
#
# WARNING! All changes made in this file will be lost!


from PyQt5 import QtCore, QtGui, QtWidgets
import sqlite3
import datetime
import PyQt5
from PyQt5.QtCore import QDate, Qt
from PyQt5.QtGui import (QColor, QFont, QTextCharFormat, QTextLength,
        QTextTableFormat)
from PyQt5.QtWidgets import (QApplication, QComboBox, QDateTimeEdit,
        QHBoxLayout, QLabel, QMainWindow, QSpinBox, QTextBrowser, QVBoxLayout,
        QWidget)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(1200, 900)
        MainWindow.setMinimumSize(QtCore.QSize(0, 0))
        MainWindow.setMaximumSize(QtCore.QSize(1200, 900))
        MainWindow.setStyleSheet("background-color: rgb(200, 200, 200);")
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.Header = QtWidgets.QTextEdit(self.centralwidget)
        self.Header.setEnabled(False)
        self.Header.setGeometry(QtCore.QRect(-10, 0, 1300, 110))
        self.Header.setMinimumSize(QtCore.QSize(1300, 110))
        self.Header.setMaximumSize(QtCore.QSize(1300, 110))
        self.Header.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(255, 255, 255);\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.Header.setObjectName("Header")
        self.LECTURP = QtWidgets.QLabel(self.centralwidget)
        self.LECTURP.setGeometry(QtCore.QRect(512, 2, 180, 61))
        self.LECTURP.setStyleSheet("color: rgb(0, 176, 240);\n"
"font: 8pt \"MS Shell Dlg 2\";\n"
"text-decoration: underline;\n"
"background-color: rgb(255, 255, 255);\n"
"font: 28pt \"Calbri\";\n"
"text-decoration: underline;")
        self.LECTURP.setObjectName("LECTURP")
        self.LecturpBanner = QtWidgets.QLabel(self.centralwidget)
        self.LecturpBanner.setGeometry(QtCore.QRect(320, 60, 561, 31))
        self.LecturpBanner.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"color: rgb(0, 176, 240);\n"
"font: 14pt \"Calibri\";")
        self.LecturpBanner.setObjectName("LecturpBanner")
        self.calendarWidget = QtWidgets.QCalendarWidget(self.centralwidget)
        self.calendarWidget.setGeometry(QtCore.QRect(30, 110, 1141, 661))
        self.calendarWidget.setStyleSheet("alternate-background-color: rgb(255, 255, 255);\n"
"font: 75 16pt \"MS Shell Dlg 2\";\n"
"background-color: rgb(200, 200, 200);\n"
"selection-background-color: rgb(255, 0, 0);")
        self.calendarWidget.setObjectName("calendarWidget")
        self.DateInfoOutput = QtWidgets.QLabel(self.centralwidget)
        self.DateInfoOutput.setGeometry(QtCore.QRect(30, 778, 1141, 97))
        self.DateInfoOutput.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(0, 0, 0);\n"
"font: 16pt \"Calibri\";\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.DateInfoOutput.setText("")
        self.DateInfoOutput.setObjectName("DateInfoOutput")
        self.WeekNumber = QtWidgets.QLabel(self.centralwidget)
        self.WeekNumber.setGeometry(QtCore.QRect(56, 168, 113, 49))
        self.WeekNumber.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"font: 16pt \"MS Shell Dlg 2\";")
        self.WeekNumber.setObjectName("WeekNumber")
        self.calendarWidget.raise_()
        self.Header.raise_()
        self.LECTURP.raise_()
        self.LecturpBanner.raise_()
        self.DateInfoOutput.raise_()
        self.WeekNumber.raise_()
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

        self.editor = QTextBrowser()


        self.calendarWidget.clicked[QDate].connect(self.dateClicked)


    def dateClicked(self, clickedDate):
        connection = sqlite3.connect("Calendardatabase.db") 
        crsr = connection.cursor() 
        crsr.execute(
            'SELECT Text FROM Calendar WHERE Day = ? AND Month = ? AND YEAR = ?', 
            (clickedDate.day(), clickedDate.month(), clickedDate.year()))
        result = crsr.fetchone()

        if result:
            self.DateInfoOutput.setText(result[0])
        else:
            self.DateInfoOutput.setText('')


    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.LECTURP.setText(_translate("MainWindow", "LECTURP"))
        self.LecturpBanner.setText(_translate("MainWindow", "Lecture, Exam, Coursework, Timetable, Uploader and Reminder Program."))
        self.WeekNumber.setText(_translate("MainWindow", "Week No."))


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_())

我试着跟随你的评论，我做到了：

    crsr.execute('SELECT Date FROM Calendar2 WHERE Number = ?', (Count,))
        Dates3 = crsr.fetchone()
        Dates3 = str(Dates3)
        Dates3 = Dates3.replace("'", "")
        Dates3 = Dates3.replace('(', '')
        Dates3 = Dates3.replace(')', '')
        Dates3 = Dates3.replace(',', '')
        print(All_Dates)

        print(Dates3)
        Dates3 = Dates3.replace('/', ',')


        self.dates = { QDate(2020, 3, 20): ["Um Sure"] }

        format = QTextCharFormat() 
        format.setBackground(QColor("salmon")) 
        self.calendarWidget.setDateTextFormat(Dates3, format)

无论何时尝试运行此操作，都会出现以下错误：

Message=setDateTextFormat（self，Union[QDate，datetime.date]，QTextCharFormat）：参数1具有意外的类型“str”

我尝试过使用self.dates变量，但也不起作用。我不确定如何将日期转换为输出的QDate部分可以接受的格式

好的，一切都正常，但当我做这个while循环时，我只是想知道我是做错了python还是做错了QT

    Count = 1 
        while Count <= list3:
            connection = sqlite3.connect("Calendardatabase.db") 
            # This is the code for the database cursor 


            Current_Day = datetime.date.today().strftime("%A,")
            Current_Date = datetime.date.today().strftime("%d")
            Current_Month = datetime.date.today().strftime("%B")


            Combined_Date = ("It is a " + Current_Day + " It is the " + Current_Date + " of " + Current_Month)

            Combined_Date = str(Combined_Date)

            self.DateInfoOutput.setText(Combined_Date)

            cursor = self.editor.textCursor()



            crsr.execute('SELECT Date FROM Calendar2 WHERE Number = ?', (Count,))
            Dates3 = crsr.fetchone()
            Dates3 = str(Dates3)
            Dates3 = Dates3.replace("'", "")
            Dates3 = Dates3.replace('(', '')
            Dates3 = Dates3.replace(')', '')
            Dates3 = Dates3.replace(',', '')


            crsr.execute('SELECT Text FROM Calendar2 WHERE Number = ?', (Count,))
            Text = crsr.fetchone()
            Text = str(Text)
            Text = Text.replace("'", "")
            Text = Text.replace('(', '')
            Text = Text.replace(')', '')
            Text = Text.replace(',', '')


            print(Dates3)

            Dates3 = Dates3.replace('/', ' ')
            Dates3 = Dates3.replace("'", '')
            Dates3.split()

            sqlDay = int(Dates3[0:2])
            sqlMonth = int(Dates3[3:4])
            sqlYear = int(Dates3[6:10])



            self.dates = { QDate(sqlYear, sqlMonth, sqlDay): ["Hi"]}



            format = QTextCharFormat() 
            format.setBackground(QColor("lightblue")) 


            Count = Count + 1
            for date, value in self.dates.items(): 
                self.calendarWidget.setDateTextFormat(date, format)
                self.DateInfoOutput.setText(Text)
            else:
                self.DateInfoOutput.setText(Combined_Date)
        else:
            self.DateInfoOutput.setText(Combined_Date)

Count=1
当计数时，这种情况的程序是：


对数据库进行查询
以字符串形式获取日期
使用指向适当格式的方法将字符串转换为，然后
在“使用”对话框中设置该日期的格式

导入操作系统
导入sqlite3
从PyQt5导入QtCore、QtGui、QtWidgets
CURRENT_DIR=os.path.dirname（os.path.realpath（uu文件_uu））
如果名称=“\uuuuu main\uuuuuuuu”：
导入系统
app=qtwidts.QApplication（sys.argv）
calendar=QtWidgets.QCalendarWidget（）
calendar.show（）
connection=sqlite3.connect（os.path.join（当前目录，“Calendardatabase.db”））
crsr=connection.cursor（）
crsr.execute（““从日历中选择日期2”）
日期\格式=“d/M/yyyy”
cell_format=QtGui.QTextCharFormat（）
单元格格式。背景（QtGui.QColor（“红色”））
对于crsr.fetchall（）中的行：
日期\u str，*\u=行
dt=QtCore.QDate.fromString（日期字符串，日期格式）
如果dt.isValid（）：
calendar.setDateTextFormat（dt，cell_格式）
其他：
打印（“{}与格式{}不匹配”。格式（日期\u str，日期\u格式））
sys.exit（app.exec_（））
在获得@eyllanesc的帮助后，我已经完全完成了我的程序，我将把我的程序留在这里，这样，如果有人卡住了，他们可以使用我的程序作为指南，或者在任何情况下都可以提供帮助

    # -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'Calendar.ui'
#
# Created by: PyQt5 UI code generator 5.14.1
#
# WARNING! All changes made in this file will be lost!


from PyQt5 import QtCore, QtGui, QtWidgets
import sqlite3
import datetime
import PyQt5
from PyQt5.QtCore import QDate, Qt
from PyQt5.QtGui import (QColor, QFont, QTextCharFormat, QTextLength,
        QTextTableFormat)
from PyQt5.QtWidgets import (QApplication, QComboBox, QDateTimeEdit,
        QHBoxLayout, QLabel, QMainWindow, QSpinBox, QTextBrowser, QVBoxLayout,
        QWidget)

class Ui_CalendarWidget(object):
    def setupUi(self, CalendarWidget):
        CalendarWidget.setObjectName("CalendarWidget")
        CalendarWidget.resize(1200, 900)
        CalendarWidget.setMinimumSize(QtCore.QSize(0, 0))
        CalendarWidget.setMaximumSize(QtCore.QSize(1200, 900))
        CalendarWidget.setStyleSheet("background-color: rgb(200, 200, 200);")
        self.centralWidget = QtWidgets.QWidget(CalendarWidget)
        self.centralWidget.setObjectName("centralWidget")
        self.Header = QtWidgets.QTextEdit(self.centralWidget)
        self.Header.setEnabled(False)
        self.Header.setGeometry(QtCore.QRect(-10, 0, 1300, 110))
        self.Header.setMinimumSize(QtCore.QSize(1300, 110))
        self.Header.setMaximumSize(QtCore.QSize(1300, 110))
        self.Header.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(255, 255, 255);\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.Header.setObjectName("Header")
        self.LECTURP = QtWidgets.QLabel(self.centralWidget)
        self.LECTURP.setGeometry(QtCore.QRect(512, 2, 180, 61))
        self.LECTURP.setStyleSheet("color: rgb(0, 176, 240);\n"
"font: 8pt \"MS Shell Dlg 2\";\n"
"text-decoration: underline;\n"
"background-color: rgb(255, 255, 255);\n"
"font: 28pt \"Calbri\";\n"
"text-decoration: underline;")
        self.LECTURP.setObjectName("LECTURP")
        self.LecturpBanner = QtWidgets.QLabel(self.centralWidget)
        self.LecturpBanner.setGeometry(QtCore.QRect(320, 60, 561, 31))
        self.LecturpBanner.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"color: rgb(0, 176, 240);\n"
"font: 14pt \"Calibri\";")
        self.LecturpBanner.setObjectName("LecturpBanner")
        self.calendarWidget = QtWidgets.QCalendarWidget(self.centralWidget)
        self.calendarWidget.setGeometry(QtCore.QRect(30, 110, 1141, 661))
        self.calendarWidget.setStyleSheet("alternate-background-color: rgb(255, 255, 255);\n"
"font: 75 16pt \"MS Shell Dlg 2\";\n"
"background-color: rgb(200, 200, 200);\n"
"selection-background-color: rgb(255, 0, 0);")
        self.calendarWidget.setObjectName("calendarWidget")
        self.DateInfoOutput = QtWidgets.QLabel(self.centralWidget)
        self.DateInfoOutput.setGeometry(QtCore.QRect(30, 778, 1141, 97))
        self.DateInfoOutput.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"border-color: rgb(0, 0, 0);\n"
"font: 16pt \"Calibri\";\n"
"border-width : 1.2px;\n"
"border-style:inset;")
        self.DateInfoOutput.setText("")
        self.DateInfoOutput.setObjectName("DateInfoOutput")
        self.WeekNumber = QtWidgets.QLabel(self.centralWidget)
        self.WeekNumber.setGeometry(QtCore.QRect(56, 168, 113, 49))
        self.WeekNumber.setStyleSheet("background-color: rgb(255, 255, 255);\n"
"font: 16pt \"MS Shell Dlg 2\";")
        self.WeekNumber.setObjectName("WeekNumber")
        self.calendarWidget.raise_()
        self.Header.raise_()
        self.LECTURP.raise_()
        self.LecturpBanner.raise_()
        self.DateInfoOutput.raise_()
        self.WeekNumber.raise_()
        CalendarWidget.setCentralWidget(self.centralWidget)
        self.statusbar = QtWidgets.QStatusBar(CalendarWidget)
        self.statusbar.setObjectName("statusbar")
        CalendarWidget.setStatusBar(self.statusbar)

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

        self.editor = QTextBrowser()


        self.calendarWidget.clicked[QDate].connect(self.dateClicked)

        connection = sqlite3.connect("Calendardatabase.db")
        crsr = connection.cursor()

        Current_Day = datetime.date.today().strftime("%A,")
        Current_Date = datetime.date.today().strftime("%d")
        Current_Month = datetime.date.today().strftime("%B")

        Combined_Date = ("It is a " + Current_Day + " It is the " + Current_Date + " of " + Current_Month)

        Combined_Date = str(Combined_Date)

        self.DateInfoOutput.setText(Combined_Date)


        #This is where the SQL Data is converted to d/M/yyyy and is then highlighted onto the calendar widget itself.

        connection = sqlite3.connect("Calendardatabase.db")
        crsr = connection.cursor()
        crsr.execute("""SELECT Date FROM Calendar2""")

        date_format = "d/M/yyyy"
        cell_format = QtGui.QTextCharFormat()
        cell_format.setBackground(QtGui.QColor("lightblue"))

        for row in crsr.fetchall():
            date_str, *_ = row
            dt = QtCore.QDate.fromString(date_str, date_format)
            if dt.isValid():
                self.calendarWidget.setDateTextFormat(dt, cell_format)
            else:
                self.DateInfoOutput.setText("{} does not match format {}".format(date_str, date_format))









    def dateClicked(self, clickedDate):
        connection = sqlite3.connect("Calendardatabase.db") 
        # This is the code for the database cursor 
        crsr = connection.cursor() 
        Count = 1
        crsr.execute('SELECT Day FROM Calendar WHERE Number = ?', (Count,))
        RawDay = crsr.fetchone()
        Day = str(RawDay)
        Day = Day.replace('(', '')
        Day = Day.replace(')', '')
        Day = Day.replace(',', '')
        Day = int(Day)

        crsr.execute('SELECT Month FROM Calendar WHERE Number = ?', (Count,))
        RawMonth = crsr.fetchone()
        Month = str(RawMonth)
        Month = Month.replace('(', '')
        Month = Month.replace(')', '')
        Month = Month.replace(',', '')
        Month = int(Month)

        crsr.execute('SELECT Year FROM Calendar WHERE Number = ?', (Count,))
        RawYear = crsr.fetchone()
        Year = str(RawDay)
        Year = Year.replace('(', '')
        Year = Year.replace(')', '')
        Year = Year.replace(',', '')
        Year = int(Year)        


        Current_Day = datetime.date.today().strftime("%A,")
        Current_Date = datetime.date.today().strftime("%d")
        Current_Month = datetime.date.today().strftime("%B")


        Combined_Date = ("It is a " + Current_Day + " It is the " + Current_Date + " of " + Current_Month)

        Combined_Date = str(Combined_Date)

        self.DateInfoOutput.setText(Combined_Date)

        cursor = self.editor.textCursor()

        All_Dates = (Day, Month, Year)

        self.selectedDate = QDate.currentDate()
        connection = sqlite3.connect("Calendardatabase.db") 
        crsr = connection.cursor() 
        crsr.execute(
            'SELECT Text FROM Calendar WHERE Day = ? AND Month = ? AND YEAR = ?', 
            (clickedDate.day(), clickedDate.month(), clickedDate.year()))
        result = crsr.fetchone()

        self.Date = (clickedDate.day() , '/' , clickedDate.month() , '/' , clickedDate.year())



        if result:
            self.DateInfoOutput.setText(result[0])


        else:
            self.DateInfoOutput.setText(Combined_Date)








    def retranslateUi(self, CalendarWidget):
        _translate = QtCore.QCoreApplication.translate
        CalendarWidget.setWindowTitle(_translate("CalendarWidget", "CalendarWidget"))
        self.LECTURP.setText(_translate("CalendarWidget", "LECTURP"))
        self.LecturpBanner.setText(_translate("CalendarWidget", "Lecture, Exam, Coursework, Timetable, Uploader and Reminder Program."))
        self.WeekNumber.setText(_translate("CalendarWidget", "Week No."))


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

要使此程序正常运行，您还需要我的数据库，您可以从这里获得：
如果你只是把它和程序文件放在同一个文件夹中，它应该可以工作

感谢您提供的所有帮助@eyllanesc如果没有您的帮助，我将在这个问题上被困数周：）
要做您想做的事情，您有两个步骤：1）使用SQL查询获取日期并将其转换为QDate，根据您提供的代码，您知道如何做。2） 由于您已经拥有QDate，那么您可以使用setDateTextFormat更改每个QDate的背景色，如副本所示。似乎您希望我们提供代码来制作副本粘贴，不幸的是，这不是该类型的站点。你应该使用副本中的信息来显示你的意图，而不是发布相同的问题。根据你的论点，如果2个用户发布：如何更改周末的背景色？如何更改工作日的字体颜色？它们不一样，很明显它们是一样的。在这里，你是否花了一天或几年的时间试图解决这个问题并不重要（有一个问题多年没有得到回答），所以这个论点是不相关的。我在前面的问题中看到了相同的代码，但没有显示出解决当前问题的努力。实际上，我已经告诉过你这个过程：要更改某个日期的格式，你必须构建一个包含日期信息的QDate，然后使用：
format=QTextCharFormat（）
format.setBackground（QColor（“salmon”）
你的日历。setDateTextFormat（日期，格式）
您在此处设置该日期的格式。感谢您的回复。我知道有些问题永远得不到回答，但我问你的每一个问题要么是复习了一遍，要么是结束了，所以我真的很生气你一直在关闭它们。这是我学校的一项重要工作，我一直在强调这一点，因为这是我课程的主要特点，但我无法让它发挥作用。我很抱歉有一个傲慢的语气，我只是真的很担心我不能按时完成。对于这个任务，我们都必须创建一个程序，但使用QT，但都在制作不同的程序，我是唯一一个尝试做这个功能的人。无论如何，我试着使用你的代码，我不知道该怎么做，因为。我会编辑这个问题，因为我不能把它全部写进评论中。非常感谢。它终于起作用了，我将修改我的帖子，这样人们就可以看到我完成的代码，这样，如果有人想遵循它，他们就可以