How to force built-in commands over imported.

[Maurice van de Rijzen]

Dear all.
I'm a newbie on the field of python, therefore the answer to my question 
may be simple.
There is a built-in commans called open(fileName). There is also a 
open() command in the os-module open which needs more than the fileName. 
  Originally I didn't import the os-module and everything worked fine. 
However, when I imported the os-module I received an error that open 
needed more arguments. How can I force to take the built-in open() 
instead of the open() in the os-module.

Gr,
Maurice