如何使用wxpython在工具栏项之间引入垂直线

import wx

class MyApp(wx.App):
    def OnInit(self):
        frame = MyFrame(None, title="工具栏示例")
        self.SetTopWindow(frame)
        frame.Show()
        return True

class MyFrame(wx.Frame):
    def __init__(self, parent, title):
        super(MyFrame, self).__init__(parent, title=title)

        self.InitUI()

    def InitUI(self):
        panel = wx.Panel(self)

        toolbar = self.CreateToolBar()
        toolbar.SetToolBitmapSize((16, 16))

        # 添加工具栏项
        toolbar.AddTool(wx.ID_NEW, 'New', wx.Bitmap('new.png'))
        toolbar.AddTool(wx.ID_OPEN, 'Open', wx.Bitmap('open.png'))
        toolbar.AddSeparator()  # 添加分隔符
        toolbar.AddTool(wx.ID_SAVE, 'Save', wx.Bitmap('save.png'))
        toolbar.AddSeparator()  # 添加分隔符
        toolbar.AddTool(wx.ID_EXIT, 'Exit', wx.Bitmap('exit.png'))
        toolbar.Realize()

        # 添加垂直线
        toolbar.AddSeparator()  # 添加分隔符
        dc = wx.ClientDC(toolbar)
        dc.SetPen(wx.Pen(wx.BLACK, 1))
        dc.DrawLine(0, 0, 0, toolbar.GetSize().GetHeight())

        panel.SetSizerAndFit(toolbar)
        self.SetSize((300, 200))
        self.Centre()

if __name__ == '__main__':
    app = MyApp()
    app.MainLoop()