I learned from the front set aggregate , Let's learn one by one in this section set Type provides methods . First , adopt dir(set) Command to see what it does ：
>>> dir(set)
['add', 'clear', 'copy', 'difference', 'difference_update', 'discard', 'intersection', 'intersection_update', 'isdisjoint', 'issubset', 'issuperset', 'pop', 'remove', 'symmetric_difference', 'symmetric_difference_update', 'union', 'update']
The specific syntax structure and functions of each method are shown in the following table .
