在Python下使用GTK无法直接使用pip安装PyGObject库
打卡MSYS终端，依次执行：

pacman -Suy
pacman -S mingw-w64-x86_64-gtk4 mingw-w64-x86_64-python3 mingw-w64-x86_64-python3-pip mingw-w64-x86_64-python3-gobject mingw-w64-x86_64-libadwaita mingw-w64-x86_64-python-autopep8 mingw-w64-x86_64-python-pylint
pacman -S python3
python3 --version

import gi
gi.require_version("Gtk", "4.0")
from gi.repository import Gtk

def on_activate(app):
    win = Gtk.ApplicationWindow(application=app)
    btn = Gtk.Button(label="Hello, World!")
    btn.connect('clicked', lambda x: win.close())
    win.set_child(btn)
    win.present()

app = Gtk.Application(application_id='org.gtk.Example')
app.connect('activate', on_activate)
app.run(None)

参考链接

PyObject
Python和Gtk 4:在Windows上准备开发环境