This is a simple example: my 'low battery' warning on Kubuntu
#!/usr/bin/env python
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtNetwork import *
import sys
app = QApplication(sys.argv)
font = QFont("Optima",100)
class Label(QLabel):
clicked = pyqtSignal()
def __init__(self,*xs,**kw):
super().__init__(*xs,**kw)
self.mouseDown = False
def mousePressEvent(self,e):
self.mouseDown = True
def mouseReleaseEvent(self,e):
if self.mouseDown:
app.exit(0)
self.clicked.emit()
self.mouseDown = False
super().mouseReleaseEvent(e)
w = Label("Low battery!")
w.setFont(font)
w.setStyleSheet("padding: 0.3em")
w.show()
exit(app.exec())