如何在窗口打开时在输出中显示PySimpleGUI默认文本

import PySimpleGUI as sg

layout = [[sg.Output(size=(40, 10))],
          [sg.Button('显示默认文本')]]
window = sg.Window('窗口标题', layout)

while True:
    event, values = window.read()
    if event == sg.WINDOW_CLOSED:
        break
    elif event == '显示默认文本':
        print('这是默认文本')

window.close()

import PySimpleGUI as sg

layout = [[sg.Output(size=(40, 10))],
          [sg.Button('显示默认文本')]]
window = sg.Window('窗口标题', layout)

while True:
    event, values = window.read()
    if event == sg.WINDOW_CLOSED:
        break
    elif event == '显示默认文本':
        print('这是默认文本')

window.close()