1.在尾部添加一項
add(...)
This has no effect if the element is already present
>>> a = set([1,2,3,4,5])
>>> a.add('shaw')
>>> a
set([1, 2, 3, 4, 5, 'shaw'])
2．清空集合中所有元素
clear(...)
Remove all elements from this set
>>>a = set([1, 2, 3, 4, 5, 'shaw'])
>>>a.clear()
>>>a
set([])
3.返回一個新集合，但是新集合中的元素，a中有，b中沒有
difference(...)
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> b = set([2,3,5,'sam'])
>>> a.difference(b)
set([1, 4, 'shaw'])
4.從set a中刪除，集合a和集合b同時擁有的元素
difference_update(...)
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> b = set([2,3,5,'sam'])
>>> a.difference_update(b)
>>> a
set([1, 4, 'shaw'])
>>> b
set([2, 3, 5, 'sam'])
5.刪除set中指定元素（即使這個元素不存在與這個集合中，不會報錯）
discard(...)
Remove an element from a set if it is amember.f the element is not a member, do nothing.
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> a.discard('5')
>>> a
set([1, 2, 3, 4, 5, 'shaw'])
>>> a.discard('sam')
>>> a
set([1, 2, 3, 4, 5, 'shaw'])
6.返回一個新集合，新集合元素由set a和set b的交集組成
intersection(...)
Return the intersection of two or more setsas a new set.
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> b = set([2,3,5,'sam'])
>>> a.intersection(b) 等同於 a & b
set([2, 3, 5])
7.從set a中刪除，a和b交集之外的元素
intersection_update(...)
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> b = set([2,3,5,'sam'])
>>> a.intersection_update(b)
>>> a
set([2, 3, 5])
8.判斷兩個集合是否有交集，如果有，則返回True,否則返回False
isdisjoint(...)
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> b = set([2,3,5,'sam'])
>>> a.isdisjoint(b)
False
>>> c = set([9,'alices'])
>>> a.isdisjoint(c)
True
9．測試一個集合中的元素是否都在另一個元素中（即測試集合b是否是集合a的子集）
issubset(...)
Report whether another set contains this set
注：
issuperset(...)
Report whether this set contains another set
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> b = set([2,3,5,'sam'])
>>> c = set([5,'shaw'])
>>> b.issubset(a)
False
>>> c.issubset(a) 等同於 c <= a
True
10.刪除一個元素（默認刪除第一項），如果要刪除的元素不存在，則報keyerror
pop(...)
>>>a = set([1, 2, 3, 4, 5, 'shaw'])
>>>a.pop()
1
>>>a
set([2,3, 4, 5, 'shaw'])
11. 刪除指定元素，如果要刪除的元素不存在，則報keyerror
remove(...)
>>> a = set([1, 2, 3, 4, 5,'shaw'])
>>> a.remove(1)
>>> a
set([2, 3, 4, 5, 'shaw'])
>>> a.remove('shaw')
>>> a
set([2, 3, 4, 5])
12.對稱差集（此元素在a中有且b中沒有，和b中有且a中沒有的元素）
symmetric_difference(...)
>>> a = set('abcdef')
>>> b = set('abcklyt')
>>> a.symmetric_difference(b)
set(['e', 't', 'f', 'y', 'k', 'l', 'd'])
>>> a ^ b
set(['e', 't', 'f', 'y', 'k', 'l', 'd'])
13.取並集（返回一個新的 set 包含 s 和t 中的每一個元素）
union(...)
>>> a = set('acdf')
>>> b = set('adkh')
>>> a.union(b)
set(['a', 'c', 'd', 'f', 'h', 'k'])
>>> a | b
set(['a', 'c', 'd', 'f', 'h', 'k'])
14.向集合a中添加元素（添加另一個集合時，會去除重複的元素）
update(...)
>>> a = set('acdf')
>>> b = set('adkh')
>>> a.update(b)
>>> a
set(['a', 'c', 'd', 'f', 'h', 'k'])
>>> a = set('acdf')
>>> b = set('adkh')
>>> a |= b
>>> a
set(['a', 'c', 'd', 'f', 'h', 'k'])
>>> a= set('shaw')
>>> a.update('bnga')
>>> a
set(['a', 'b', 'g', 'h', 'n', 's', 'w'])