Python中集合函数Set的使用详解

In Python, a set is an unordered collection of unique elements, primarily used for checking membership and eliminating duplicate entries. It also supports mathematical operations such as union, intersection, difference, and symmetric difference.

This article presents common use cases for set to demonstrate its basic functionality:

1. Creating an Empty Set
   An empty set is created using s = set().
2. Creating a Set from a List
   A set is created from a list using s = set([1, 2, 3, 4, 5]).
3. Adding Elements
   New elements can be added to a set using s.add(4).
4. Deleting Elements
   Elements can be removed from a set with s.remove(2).
5. Checking for Membership
   Use 2 in s to check if an element is in the set.
6. Getting the Length
   The size of the set can be determined using len(s).
7. Union of Sets
   The union of two sets can be obtained with s1 | s2.
8. Intersection of Sets
   The intersection is calculated with s1 & s2.
9. Difference of Sets
   The difference between two sets is given by s1 - s2.
10. Symmetric Difference of Sets
    The symmetric difference, elements not in the intersection, is obtained with s1 ^ s2.
11. Filtering Duplicate Elements
    Duplicate elements in a list can be filtered by converting the list to a set.
12. Union of Multiple Sets
    The union of multiple sets can be performed using s1 | s2 | s3.

The examples provided demonstrate the versatility of sets in Python, which ranges from simple element management to complex data processing and mathematical computations. Understanding these use cases can enhance one's programming proficiency.