判断是否相交
>>> x1 = {'foo', 'bar', 'baz'}>>> x2 = {'baz', 'qux', 'quux'}>>> x1.isdisjoint(x2)False>>> x2 - {'baz'}{'quux', 'qux'}>>> x1.isdisjoint(x2 - {'baz'})True
判断是否是子集
>>> x1 = {'foo', 'bar', 'baz'}>>> x1.issubset({'foo', 'bar', 'baz', 'qux', 'quux'})True>>> x2 = {'baz', 'qux', 'quux'}>>> x1 <= x2False
判断是否交集
>>> x1 = {'foo', 'bar', 'baz'}>>> x1.issuperset({'foo', 'bar'})True>>> x2 = {'baz', 'qux', 'quux'}>>> x1 >= x2False
