[Tutor] working with multiple sets

[kevin parks]

I am doing some simple things with sets and so far have had a lot of  
success with python's built-in sets, which is such a great new(ish)  
"batteries included" type python data type.

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#!/usr/bin/env python

def test():
	x = range(10)
	y = range(5, 15)
	z = range(8, 22)
	setx = set(x)
	sety = set(y)
	setz = set(z)
	print "\n", "x = ", x, "\n", "y = ", y, "\n", "z = ", z, "\n" * 2
	overlap1 = setx.intersection(sety)
	overlap1 = sorted(list(overlap1))
	print "overlap of x and y:", overlap1
	#
	overlap2 = sety.intersection(setz)
	overlap2 = sorted(list(overlap2))
	print "overlap of y and z:", overlap2
	#
	overlap3 = setx.intersection(setz)
	overlap3 = sorted(list(overlap3))
	print "overlap of x and z:", overlap3
	
if __name__ == "__main__":
	test()

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so silly stuff like that works fine. But i want to do a little more  
than that. I want to be able to look at a number/item and see which  
lists it is in so that i could maybe have a master list of all the  
data, a superset, and then an indication of which lists that data  was  
in, as some items will only be in one list, some will appear in two  
lists (x & y, or x & z or y & z) and a small handful will be in all  
three lists.

0 - x
1 - x
2 - x
3 - x
4 - x
5 - x, y
6 - x, y
7 - x, y
8 - x, y, z
9 - x, y, z
10 - y, x

etc.

Of course the whole point of this is that the sets will be more  
complicated than 0-9, 5-14, and 8-21 and additionally, the sets may  
not be a list of numbers but eventually a list of strings.

So the steps would be to create the superset
then test for membership for each list?

I kinda get it, the thing that warps my brain is the idea that there  
are more than 2 lists now to test against.... eventually my script  
needs to accommodate 4, 5, 6 sets.. but i would just like to see if i  
can get 3 sets to work first.