My objective is to use a QSpinBox to display the numbers from 0 to 9999 with the increasement of 1 using 4-digits format.
I managed to set the Maximum value 9999 by using setMaximum command. But I can't seems to find a way to display the values in 4digits format (eg. 0000, 0001,0002). Whenever i set the value to 0000  using setValue , the SpinBox display as 0. 
How do i display the numbers in 4-digits format (i.e adding leading zero as required) in QSpinBox?
To do what you want, just set the "prefix" attribute of the spinbox widget to "000". This will then pad values to be 0001, 0002, etc.
PyQt4 QSpinBox value format