#!/usr/bin/python

s = set(['a', 'a', 'b', 'c', 'd']); #['a', 'b', 'c', 'd']
s2 = set(['a', 'd', 'e', 'f']);

#access element
for e in s:
    print e,
print

print s|s2; #union
print s&s2; #intersection
print s-s2; #difference

s.add('g'); #['a', 'b', 'c', 'd', 'g']
s.remove('d'); #remove element; raise KeyError if not present
s.discard('c'); #remove if present
s.pop(); #remvoe an arbitrary element
if s.issuperset(set(['b'])):
    print '[b, g] is the super set of [b]'
s.clear(); #remove all element in set
		

#!/usr/bin/python

s = frozenset(['a', 'a', 'b', 'c', 'd']); #['a', 'b', 'c', 'd']
s2 = frozenset(['a', 'd', 'e', 'f']);

print s|s2; #union
print s&s2; #intersection
print s-s2; #difference

if s.issuperset(frozenset(['b'])):
    print '[a, b, c, d] is the super set of [b]'