Minimize button in a QDialog in PyQt

Often it is easy to write a small application in PyQt as a QDialog (instead of using a QMainWindow). If it is intended as an application that has to be open for a longer time (e.g. while the user is using other programs) it is nice if the program can minimize (e.g. when the user clicks the show desktop button in windows (or the nice windows-key+d key shortcut). However, by default the QDialog window only has a close button. Luckily adding minimize and maximize buttons is easy:

from PyQt4.QtCore import *
from PyQt4.QtGui import *


class MainForm(QDialog):

    def __init__(self, fn=None,parent=None):
        super(MainForm, self).__init__(parent,\
           flags=Qt.WindowMinimizeButtonHint|Qt.WindowMaximizeButtonHint)

Other flags can be found here