names = ['Cls', 'Bck', '', 'Close',
'7', '8', '9', '/',
'4', '5', '6', '*',
'1', '2', '3', '-',
'0', '.', '=', '+']
positions = [(i,j) for i in range(1,6) for j in range(4)]
buttons = {}
for position, name in zip(positions, names):
if name == '':
continue
btn = QPushButton(name)
buttons[name] = btn
grid.addWidget(btn, *position)