|  clear(...) 清空一个集合

|      Remove all elements from this set.

>>>set1.clear()>>>set1

set()

|  copy(...) 影子复制，指向同一个内存地址

|      Return a shallow copy of a set. |

>>> list1

[3, 2, 1, 1, 2, 3, 4, 5]

>>> list2

[3, 4, 5, 6, 7, 8]

>>> set1=set(list1)>>>id(set1)140138768485512>>> set3=set1.copy()>>>id(set3)140138695576712

|  difference(...) 差集，格式set1.difference(set2)，求in list1 not in list2的集合

|      Return the difference of two or more sets as a new set. |

|      (i.e. all elements that are in this set but not the others.)

>>>set1

{1, 2, 3, 4, 5}>>>set2

{3, 4, 5, 6, 7, 8}>>>set1.difference(set2)

{1, 2}

|  difference_update(...) 删除在本集合同时也在其他集合的元素，差集

|      Remove all elements of another set from this set. |

>>> set1=set(list1)

>>> set2=set(list2)

>>> set1,set2

({1, 2, 3, 4, 5}, {3, 4, 5, 6, 7, 8})

>>> set1=set(list1)>>> set2=set(list2)>>>set2.difference_update(set1)>>>set2

{6, 7, 8}

|  discard(...) 删除一个在本集合中的元素

|      Remove an element from a set if it is a member.

|

|      If the element is not a member, do nothing. |

>>> set3=set([1,2,3,'a','b','c'])>>> set3.discard(1)>>>set3

{2, 3, 'c', 'b', 'a'}>>> set3.discard('a')>>>set3

{2, 3, 'c', 'b'}>>> set3.discard('dd')>>>set3

{2, 3, 'c', 'b'}

|  intersection(...)并集，同时在两个集合中的元素

|      Return the intersection of two sets as a new set.

|

|      (i.e. all elements that are in both sets.) |

>>>set1

{1, 2, 3, 4, 5}>>>set2

{3, 4, 5, 6, 7, 8}>>>set1.intersection(set2)

{3, 4, 5}>>>set2.intersection(set1)

{3, 4, 5}

|  intersection_update(...) 交集

|      Update a set with the intersection of itself and another. |

>>>set1,set2

({1, 2, 3, 4, 5}, {3, 4, 5, 6, 7, 8})>>>set1.intersection_update(set2)>>>set1

{3, 4, 5}

|  isdisjoint(...) 返回布尔值，判断两个集合是否没有并集

|      Return True if two sets have a null intersection.

|

>>>set1,set2,set3,set4

({3, 4, 5}, {3, 4, 5, 6, 7, 8}, {2, 3, 'c', 'b'}, {'y', 'x', 'z'})>>>set1.isdisjoint(set2)

False>>>set1.isdisjoint(set4)

True

|  issubset(...) 返回布尔值，判断前一个集合是否是后一个集合的子集

|      Report whether another set contains this set. |

>>>set1

{3, 4, 5}>>>set5

{3, 4}>>>set5.issubset(set1)

True

|  issuperset(...) 返回布尔值，判断前一个集合是否是后一个集合的父集

|      Report whether this set contains another set. |

>>>set1

{3, 4, 5}>>>set5

{3, 4}>>>set1.issuperset(set5)

True

|  pop(...) 随机删除一个集合元素，返回被删除元素，空集合删除则报错

|      Remove and return an arbitrary set element.

|      Raises KeyError if the set is empty. |

>>>set1

{3, 4, 5}>>>set1.pop()3

>>>set1

{4, 5}>>>set1.pop()4

>>>set1.pop()5

>>>set1.pop()

Traceback (most recent call last):

File"", line 1, in KeyError:'pop from an empty set'

|  remove(...) 删除指定在集合中的元素

|      Remove an element from a set; it must be a member. |

>>> set1=set(list1)>>>set1

{1, 2, 3, 4, 5}>>> set1.remove(1)>>>set1

{2, 3, 4, 5}>>> set1.remove('a')

Traceback (most recent call last):

File"", line 1, in KeyError:'a'

|  symmetric_difference(...) 对称差集，集合A与集合B不相交的部分，交集的反集

|     Return the symmetric difference of two sets as a new set.

|     (i.e. all elements that are in exactly one of the sets.)

>>>set1

{1, 2, 3, 4, 5}>>> set6={4,5,6,7,8}>>>set1.symmetric_difference(set6)

{1, 2, 3, 6, 7, 8}>>>set6.symmetric_difference(set1)

{1, 2, 3, 6, 7, 8}

>>> set1,set7

({1, 2, 3, 4, 5}, {'a', 'c', 'b'})

>>> set1.symmetric_difference(set7)

{'c', 2, 3, 1, 4, 5, 'b', 'a'}