简单到离谱
a = set([1,2,3])
b = set([2,3,4])
print a-b #set([1])
print a&b #set([2, 3])
print a|b #set([1, 2, 3, 4])
print a^b #set([1, 4])
简单到离谱
a = set([1,2,3])
b = set([2,3,4])
print a-b #set([1])
print a&b #set([2, 3])
print a|b #set([1, 2, 3, 4])
print a^b #set([1, 4])