The layout of WxPython

It’s still a bit fiddly, but here it is with BoxSizer’s:

import wx

class MainWindow(wx.Frame):
    def __init__(self, parent, id, title):
        wx.Frame.__init__(self, parent, id, title, size=(900, 600) )      

        SubmissionsPanel(self)
        self.Show()

class SubmissionsPanel(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent)

        #Create some sizers:
        main_sizer = wx.BoxSizer(wx.VERTICAL)
        top_row_sizer = wx.BoxSizer(wx.HORIZONTAL);
        radio_static_box = wx.StaticBox(self, label='') #You have to add this widget to parent BEFORE
                                                        #contained widgets otherwise buttons won't operate.
        radio_static_box_sizer = wx.StaticBoxSizer(radio_static_box, wx.HORIZONTAL)

        job_static_box = wx.StaticBox(self, label='')  #You have to add this widget to parent BEFORE 
                                                       #contained widgets otherwise buttons won't operate.
        job_static_box_sizer = wx.StaticBoxSizer(job_static_box, wx.HORIZONTAL)


        '''
        radio_labels = ['Verify Mode', 'Upload Mode']
        self.radio_box = wx.RadioBox(
                self, -1, "", 
                choices=radio_labels,
        )
        '''
        #I couldn't get the radio buttons inside a RadioBox to line up vertically
        #with the checkbox, so I did the following:
        radio1 = wx.RadioButton(self, label='Verify Mode', style=wx.RB_GROUP)
        radio2 = wx.RadioButton(self, label='Upload Mode')
        radio1.Bind(wx.EVT_RADIOBUTTON, self.on_radio_click)
        radio2.Bind(wx.EVT_RADIOBUTTON, self.on_radio_click)

        radio_static_box_sizer.Add(radio1, flag=wx.BOTTOM, border=4) #To make outline line up with the outline of checkbox,txtctrl
        radio_static_box_sizer.Add(radio2, flag=wx.LEFT, border=10)

        top_row_sizer.Add(radio_static_box_sizer, flag=wx.LEFT, border=10)


        #Create Job Title widgets:
        self.check_box = wx.CheckBox(self, label="Job Title")
        self.check_box.SetValue(False)
        self.check_box.Bind(wx.EVT_CHECKBOX, self.ShowOrHideTVTitle)

        self.txtTitle = wx.TextCtrl(self, style=wx.SUNKEN_BORDER, value="Enter job title here...", size=(200, -1))
        self.txtTitle.Show(False)

        job_static_box_sizer.Add(self.check_box, flag=wx.LEFT, border=10)
        job_static_box_sizer.Add(self.txtTitle, flag=wx.RESERVE_SPACE_EVEN_IF_HIDDEN | wx.LEFT, border=10)

        top_row_sizer.Add(job_static_box_sizer, flag=wx.LEFT, border=10);

        main_sizer.Add(top_row_sizer);
        main_sizer.Add((-1, 20))  #Add 20 pixels of vertical space

        #Drag n Drop widgets:
        drag_drop_text = wx.StaticText(self, -1, 'Drag n Drop itmsp folder')
        main_sizer.Add(drag_drop_text, flag=wx.LEFT, border=10)
        main_sizer.Add((-1, 3))  #Add 3 pixels of vertical space

        third_row_sizer = wx.BoxSizer(wx.HORIZONTAL);
        self.tc_files = wx.TextCtrl(self, size=(375, 25))
        self.buttonGo = wx.Button(self, label='Submit')
        third_row_sizer.Add(self.tc_files, flag=wx.LEFT, border=10)
        third_row_sizer.Add(self.buttonGo, flag=wx.LEFT, border=10)
        main_sizer.Add(third_row_sizer)

        #Create ListCtrl:
        self.index = 0        
        self.log_text22 = wx.ListCtrl(self,size=(800,275),
                         style=wx.LC_REPORT | wx.BORDER_SUNKEN | wx.LC_SINGLE_SEL | wx.LC_VRULES | wx.LC_HRULES)

        font = wx.Font(12, wx.FONTFAMILY_DEFAULT, wx.FONTSTYLE_NORMAL, wx.FONTWEIGHT_NORMAL)
        self.log_text22.SetFont(font)

        self.log_text22.InsertColumn(1, 'Job ID', width=50, format=wx.LIST_FORMAT_CENTRE)
        self.log_text22.InsertColumn(2, 'Mode  ', width=50, format=wx.LIST_FORMAT_CENTRE)
        self.log_text22.InsertColumn(3, 'Title', width=183)
        self.log_text22.InsertColumn(4, 'Package', width=227)
        self.log_text22.InsertColumn(5, 'Submitted By', width=100)
        self.log_text22.InsertColumn(6, 'Sumbit Time', width=85)
        self.log_text22.InsertColumn(7, 'Process', width=50, format=wx.LIST_FORMAT_CENTRE)
        self.log_text22.InsertColumn(8, 'Status  ', width=50, format=wx.LIST_FORMAT_CENTRE)

        main_sizer.Add((-1, 20)) #Add 20px of vertical space
        list_sizer = wx.BoxSizer(wx.VERTICAL)
        list_sizer.Add(self.log_text22, flag=wx.LEFT, border=10)
        main_sizer.Add(list_sizer)

        #Create Quit button:
        list_sizer.Add((-1, 10))  #Add 15px of vertical space
        self.buttonClose = wx.Button(self, -1, "Quit Application")
        list_sizer.Add(self.buttonClose, flag=wx.ALIGN_CENTER | wx.TOP | wx.LEFT, border=10)

        self.SetSizer(main_sizer)


    def on_radio_click(self, evt):
        print "You clicked?"

    def ShowOrHideTVTitle(self, evt):
        element = evt.GetEventObject()
        isChecked = element.GetValue()

        if isChecked:
            self.txtTitle.Show(True)
            self.txtTitle.SetFocus()
        else:
            self.txtTitle.Show(False)
            self.tc_files.SetFocus()

    def OnSubmit(self):
        pass

    def OnClose(self):
        pass

    def showLogFile(self):
        pass

    def right_click(self):
        pass

app = wx.App(redirect=False) ##Instead of seeing just a window flash, show errors in terminal.
MainWindow(None, -1, 'Test App')
app.MainLoop()