set()集合基本操作

运用频次：☆☆

set是一个无序且不重复元素集，基本操作如下：

1. 创建set集合，会自动转换成set类型

2. add()：添加元素

 def add(self, *args, **kwargs): # real signature unknown
       # 添加元素
        """
        Add an element to a set.

        This has no effect if the element is already present.
        """
        pass

3. clear()：清除元素

 def clear(self, *args, **kwargs): # real signature unknown
        #清除元素
        """ Remove all elements from this set. """
        pass

3. copy()：浅拷贝

def copy(self, *args, **kwargs): # real signature unknown
        """ Return a shallow copy of a set. """
        pass

4. difference()：取差集，不更新原集合

def difference(self, *args, **kwargs): # real signature unknown
       # 取差集，不更新原集合，重新生成新的集合
        """
        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.)
        """
        pass

5. difference_update()：取差集，更新原集合

def difference_update(self, *args, **kwargs): # real signature unknown
       # 取差集，更新原集合，不生成新的集合
        """ Remove all elements of another set from this set. """
        pass

6. discard()：删除元素，更新原集合

def discard(self, *args, **kwargs): # real signature unknown
       # 删除指定元素，更新原集合
        """
        Remove an element from a set if it is a member.

        If the element is not a member, do nothing.
        """
        pass

7. intersection()：取交集，返回一个新的集合

def intersection(self, *args, **kwargs): # real signature unknown
       # 取交集，不更新原集合，重新生成新集合
        """
        Return the intersection of two sets as a new set.

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

8. intersection_update()：取交集，更新原集合

def intersection_update(self, *args, **kwargs): # real signature unknown
      # 取交集，更新原集合
        """ Update a set with the intersection of itself and another. """
        pass

9. isdisjoint()：判断是否有交集，无则返回True

def isdisjoint(self, *args, **kwargs): # real signature unknown
       # 若无交集，则返回True
        """ Return True if two sets have a null intersection. """
        pass

10. issubset()：判断是否是子集，是则返回True

def issubset(self, *args, **kwargs): # real signature unknown
       # 判断另一集合是否包含该集合，是则返回True
        """ Report whether another set contains this set. """
        pass

11. issuperset()：判断是否是父集，是则返回True

def issuperset(self, *args, **kwargs): # real signature unknown
       # 判断该集合是否包含另一集合，是则返回True
        """ Report whether this set contains another set. """
        pass

12. pop()：随机删除一个元素并返回，更新原集合

def pop(self, *args, **kwargs): # real signature unknown
       # 随机删除一个元素并返回，更新原集合
        """
        Remove and return an arbitrary set element.
        Raises KeyError if the set is empty.
        """
        pass

13. remove()：删除元素，更新原集合

 def remove(self, *args, **kwargs): # real signature unknown
       # 删除指定元素，无返回值，更新原集合
        """
        Remove an element from a set; it must be a member.

        If the element is not a member, raise a KeyError.
        """
        pass

14. symmetric_difference()：取差集，不更新原集合

 def symmetric_difference(self, *args, **kwargs): # real signature unknown
      # 取差集，返回一个新的集合，不更新原集合
        """
        Return the symmetric difference of two sets as a new set.

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

15. symmetric_difference_update()：取差集，更新原集合

 def symmetric_difference_update(self, *args, **kwargs): # real signature unknown
       # 取差集，更新原集合
        """ Update a set with the symmetric difference of itself and another. """
        pass

16. union()：取并集，不更新原集合

 def union(self, *args, **kwargs): # real signature unknown
       # 取并集，返回一个新的集合，不更新原集合
        """
        Return the union of sets as a new set.

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

17. update()：取并集，更新原集合

def update(self, *args, **kwargs): # real signature unknown
      # 取并集，更新原集合
        """ Update a set with the union of itself and others. """
        pass