[Pythonmac-SIG] can't exit module

[Yair Benita]

Although I import the sys module the command sys.exit() doesn't work.
Here is the most simple example:
import sys

a= 7
while a<10:
    print 'this is the while loop'
    a=a+1
    if a==9:
        print 'exiting'
        sys.exit()

I always get the same error:
SystemExit:
Traceback (innermost last):
File "Script 1", line 9, in ?
      sys.exit()

I am not sure what innermost last means.
Please advise, I can't quit a module without it.

Yair Benita
Utrecht University
The Netherlands