python集合类型set

set 类型的简单粗暴取出并集合交集  |   &

li=[11,22,33]
n_li=[44,55]
b= (list(set(li)&set(n_li)))
b2=set(li).intersection(n_li)
print (b2,b)

s = set()

s={1,2,3}

s.add(4)                          #往集合里面添加元素，如果存在的话不重复添加，无序。

s.difference_update(b）     #s集合对比b集合，并更新S集合，只保留S不重复的部分。

n=s.difference (b)             #n值等于两个集合对比，s集合比b集合多出的元素。

s.symmetric_difference(b)  #把2个不交集的部分合在一起。

intersection                      #和上面一条相反，取其交集

class set(object):

    """

    set() -> new empty set object

    set(iterable) -> new set object

     

    Build an unordered collection of unique elements.

    """

    def add(self, *args, **kwargs): # real signature unknown

        """

        Add an element to a set，添加元素

         

        This has no effect if the element is already present.

        """

        pass

 

    def clear(self, *args, **kwargs): # real signature unknown

        """ Remove all elements from this set. 清除内容"""

        pass

 

    def copy(self, *args, **kwargs): # real signature unknown

        """ Return a shallow copy of a set. 浅拷贝  """

        pass

 

    def difference(self, *args, **kwargs): # real signature unknown

        """

        Return the difference of two or more sets as a new set. A中存在，B中不存在

         

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

        """

        pass

 

    def difference_update(self, *args, **kwargs): # real signature unknown

        """ Remove all elements of another set from this set.  从当前集合中删除和B中相同的元素"""

        pass

 

    def discard(self, *args, **kwargs): # real signature unknown

        """

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

         

        If the element is not a member, do nothing. 移除指定元素，不存在不保错

        """

        pass

 

    def intersection(self, *args, **kwargs): # real signature unknown

        """

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

         

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

        """

        pass

 

    def intersection_update(self, *args, **kwargs): # real signature unknown

        """ Update a set with the intersection of itself and another.  取交集并更更新到A中 """

        pass

 

    def isdisjoint(self, *args, **kwargs): # real signature unknown

        """ Return True if two sets have a null intersection.  如果没有交集，返回True，否则返回False"""

        pass

 

    def issubset(self, *args, **kwargs): # real signature unknown

        """ Report whether another set contains this set.  是否是子序列"""

        pass

 

    def issuperset(self, *args, **kwargs): # real signature unknown

        """ Report whether this set contains another set. 是否是父序列"""

        pass

 

    def pop(self, *args, **kwargs): # real signature unknown

        """

        Remove and return an arbitrary set element.

        Raises KeyError if the set is empty. 移除元素

        """

        pass

 

    def remove(self, *args, **kwargs): # real signature unknown

        """

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

         

        If the element is not a member, raise a KeyError. 移除指定元素，不存在保错

        """

        pass

 

    def symmetric_difference(self, *args, **kwargs): # real signature unknown

        """

        Return the symmetric difference of two sets as a new set.  对称差集

         

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

        """

        pass

 

    def symmetric_difference_update(self, *args, **kwargs): # real signature unknown

        """ Update a set with the symmetric difference of itself and another. 对称差集，并更新到a中 """

        pass

 

    def union(self, *args, **kwargs): # real signature unknown

        """

        Return the union of sets as a new set.  并集

         

        (i.e. all elements that are in either set.)

        """

        pass

 

    def update(self, *args, **kwargs): # real signature unknown

        """ Update a set with the union of itself and others. 更新 """

        pass