from tkinter.filedialog import *
from tkinter.colorchooser import *


class Application(Frame):
    def __init__(self,master=None):
        super(Application, self).__init__(master)
        self.master = master
        self.textpad = None     #textpad表示Text文本框对象
        self.pack()
        self.createWidget()

    def createWidget(self):
        # 创建主菜单栏
        menubar = Menu(root)

        #创建子菜单
        menuFlie = Menu(menubar)
        menuEdit = Menu(menubar)
        menuHelp = Menu(menubar)

        # 将子菜单加入到主菜单栏
        menubar.add_cascade(label='文件(F)',menu=menuFlie)
        menubar.add_cascade(label='编辑(E)',menu=menuEdit)
        menubar.add_cascade(label='帮助(H)',menu=menuHelp)

        # 添加菜单项
        menuFlie.add_command(label='新建',accelerator='ctrl+n',command=self.newfile)
        menuFlie.add_command(label='打开',accelerator='ctrl+o',command=self.openfile)
        menuFlie.add_command(label='保存',accelerator='ctrl+s',command=self.savefile)
        menuFlie.add_separator()        #添加分割线
        menuFlie.add_command(label='退出',accelerator='ctrl+q',command=self.exit)

        #将主菜单栏加到根窗口
        root['menu'] = menubar

        #增加快捷键的处理
        root.bind('<Control-n>',lambda event:self.newfile())
        root.bind('<Control-o>',lambda event:self.openfile())
        root.bind('<Control-s>',lambda event:self.savefile())
        root.bind('<Control-q>',lambda event:self.exit())

        #文本编辑区
        self.textpad = Text(root,width=50,height=30)
        self.textpad.pack()

        # 创建上下菜单
        self.contextMenu = Menu(root)
        self.contextMenu.add_command(label='背景颜色',command=self.openAskColor)

        #为右键绑定事件
        root.bind('<Button-3>',self.createContextMenu)



    def newfile(self):
       self.textpad.delete(1.0, END)  # 把text控件中所有的内容清空
       self.filename = asksaveasfilename(title='另存为',initialfile='未命名.txt',
                                         filetypes=[('文本文档','*.txt')],defaultextension='.txt')
       self.savefile()


    def openfile(self):
        self.textpad.delete(1.0,END)        #把text控件中所有的内容清空
        with askopenfile(title='打开文本文件') as f:
            self.textpad.insert(INSERT,f.read())
            self.filename = f.name

    def savefile(self):
        with open(self.filename,'w') as f:
            c = self.textpad.get(1.0,END)
            f.write(c)

    def exit(self):
        root.quit()

    def openAskColor(self):
        s1 = askcolor(color='blue',title='选择背景颜色')  # 通过颜色框选择背景颜色
        self.textpad.config(bg=s1[1])

    def createContextMenu(self,event):
        #菜单在鼠标右键单击的坐标处显示
        self.contextMenu.post(event.x_root,event.y_root)


if __name__ == '__main__':
    root = Tk()
    root.geometry('500x300')
    root.title('记事本')
    app = Application(master=root)
    root.mainloop()

并不是完整代码，只供借鉴