So heres my code:
item = [0,1,2,3,4,5,6,7,8,9]
z = [] # list of integers
for item in z:
if item not in z:
print item
z<
Your code is a no-op. By the definition of the loop, "item" has to be in Z. A "For ... in" loop in Python means "Loop though the list called 'z', each time you loop, give me the next item in the list, and call it 'item'"
http://docs.python.org/tutorial/controlflow.html#for-statements
I think your confusion arises from the fact that you're using the variable name "item" twice, to mean two different things.