集合上的操作
與其他集
# Intersection
{1, 2, 3, 4, 5}.intersection({3, 4, 5, 6}) # {3, 4, 5}
{1, 2, 3, 4, 5} & {3, 4, 5, 6} # {3, 4, 5}
# Union
{1, 2, 3, 4, 5}.union({3, 4, 5, 6}) # {1, 2, 3, 4, 5, 6}
{1, 2, 3, 4, 5} | {3, 4, 5, 6} # {1, 2, 3, 4, 5, 6}
# Difference
{1, 2, 3, 4}.difference({2, 3, 5}) # {1, 4}
{1, 2, 3, 4} - {2, 3, 5} # {1, 4}
# Symmetric difference with
{1, 2, 3, 4}.symmetric_difference({2, 3, 5}) # {1, 4, 5}
{1, 2, 3, 4} ^ {2, 3, 5} # {1, 4, 5}
# Superset check
{1, 2}.issuperset({1, 2, 3}) # False
{1, 2} >= {1, 2, 3} # False
# Subset check
{1, 2}.issubset({1, 2, 3}) # True
{1, 2} <= {1, 2, 3} # True
# Disjoint check
{1, 2}.isdisjoint({3, 4}) # True
{1, 2}.isdisjoint({1, 4}) # False
單個元素
# Existence check
2 in {1,2,3} # True
4 in {1,2,3} # False
4 not in {1,2,3} # True
# Add and Remove
s = {1,2,3}
s.add(4) # s == {1,2,3,4}
s.discard(3) # s == {1,2,4}
s.discard(5) # s == {1,2,4}
s.remove(2) # s == {1,4}
s.remove(2) # KeyError!
設定操作返回新集,但具有相應的就地版本:
方法 | 就地操作 | 就地方法 |
---|---|---|
聯合 | s | = t |
路口 | s&= t | intersection_update |
區別 | s - = t | difference_update |
symmetric_difference | s ^ = t | symmetric_difference_update |
例如:
s = {1, 2}
s.update({3, 4}) # s == {1, 2, 3, 4}