>>> set3 = set1 & set2
intersection:取两者交集
>>> set3 = set1.intersection(set2)
intersection_update:取两者交集并将结果更新到前者中
>>> set2.intersection_update(set1)
>>> set3 = set1 | set2
union:取两者并集
>>> set3 = set1.union(set2)
>>> set3 = set1 - set2
difference:取前者与后者的差集
>>> set3 = set1.difference(set2)
intersection_update:取前者与后者的差集并将结果更新到前者中
>>> set1.difference_update(set2)
True:没有任何交集
False:有交集
True:set1是set2的子集
False:set1不是set2的子集
True:set1是set2的父集
False:set1不是set2的父集
>>> set3 = set1.symmetric_difference(set2)
symmetric_difference_update:取两者互不相同的元素并更新到前者中
>>> set1.symmetric_difference_update(set2)