python修炼4

---恢复内容开始---

集合

建立  set（） ={}，集合没有顺序，由不可改变的数字 ，字符串，元组构成

#交集
print(a&b) #a.intersection(b)

#并集
print(a|b) #a.union(b)#

#差集
print(a-b) #a.difference(b)

#交叉补集
print(a^b) #a.symmetric_difference(b)

元组的方法

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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