def initUI(self):
  names=['Cls', 'Bck', '', 'Close', '7', '8', '9', '/', '4', '5', '6', '*', '1', '2', '3', '-', '0', '.', '=', '+']
  grid = QGridLayout()
  j = 0
  pos = [(0,0), (0,1), (0,2), (0,3), (1,0), (1,1), (1,2), (1,3),
  (2,0),(2,1),(2,2),(2,3),(3,0),(3,1),(3,2),(3,3),(4,0),(4,1),(4,2),(4,3)]
  for i in names:
   button = QPushButton(i)
   if j == 2:
    grid.addWidget(QLabel(''), 0, 2)
   else:
    grid.addWidget(button, pos[j][0], pos[j][1])
   j = j + 1
  self.setLayout(grid)
  self.move(300, 150)
  self.setWindowTitle('Kalkulator')
  self.show()