Ok, for some strange reason I cannot move from the "Python27" folder:
I have tried this...
Python 2.7.3 (default, Apr 10 2012, 23:31:26)
Type "help", "copyright", "credits" or "license" for more information.
>>> from os import system
>>> system('cd ..')
os.system() is a (deprecated) function to run another program from your python program. Changing your process' working directory is different from starting another program. Use os.chdir(path) to change the current working directory and os.getcwd() to get the current working directory.