wxPython : How to change alignment StaticText after SetLabelText

If you create a frame through wxpython and change the contents of the staticText, the alignment will be initialized. How can I solve this problem? I want to align it again.

To dynamically set window alignment flags you have to

1. Get the wx.Sizer
2. Find the wx.SizerItem
3. Set the wx.SizerItem flags via SetFlag
4. call Sizer.Layout()

Here's a simple example:

import wx
import traceback


def run():
    app = wx.App()
    # create the test frame
    frame = wx.Frame(None, title="test frame", size=(500, 500))

    # create a simple boxsizer
    sizer = wx.BoxSizer()
    # create the object that we'll be dynamically adjusting
    st = wx.StaticText(frame, label="Click me")
    st.SetFont(wx.Font(30, 74, 90, wx.FONTWEIGHT_BOLD, True, "Arial Rounded"))
    # align the text to the middle initially
    sizer.Add(st, 0, wx.ALIGN_CENTER_VERTICAL)
    frame.SetSizer(sizer)

    # bind to an arbitrary event
    st.Bind(wx.EVT_LEFT_DOWN, on_click)
    # do the initial layout and show the frame
    frame.Layout()
    frame.Show()
    app.MainLoop()


def on_click(event):
    event.Skip()
    # retrieving the static text object
    st = event.GetEventObject()  # type: wx.StaticText
    # get the sizer that contains this object
    sizer = st.GetContainingSizer()  # type: wx.BoxSizer
    # find the sizer item
    # the sizer item holds the alignment information and tells
    # the sizer how to display this object
    sizer_item = sizer.GetItem(st)  # type: wx.SizerItem
    # alternate between aligning at the top & bottom
    if sizer_item.GetFlag() & wx.ALIGN_BOTTOM:
        print("Setting alignment to top")
        sizer_item.SetFlag(wx.ALIGN_TOP)
    else:
        print("Setting alignment to bottom")
        sizer_item.SetFlag(wx.ALIGN_BOTTOM)
    # call Layout to recalculate the object positions
    sizer.Layout()


if __name__ == "__main__":
    try:
        run()
    except:
        traceback.print_exc()
        input()