One: Definition
Sets are unordered, non-repeating data types that are not hashable themselves (so they cannot be used as dictionary keys), but the elements in them are hashable.
Two: involving operations
Deduplication: Turn the set into a list first, and then turn the list into a set, that is, deduplication.
Three: Collection
1 Intersection (&, intersection)
set1={1,2,"alex",}
set2={1,2,"alex",3,4}
print(set1.intersection(set2))
print(set1&set2)
output result
2 Union (|, union)
set1={1,2,"alex",}
set2={1,2,"alex",3,4}
print(set2.union(set1))
print(set1|set2)
output result
3差集（-，difference）
set1={1,2,"alex",}
set2={1,2,"alex",3,4}
print(set2.difference(set1))
print(set2-set1)
output result
4 antiintersection(^, symmetric_difference))
2,"alex",}
set2={1,2,"alex",3,4}
print(set2.symmetric_difference(set1))
print(set2^set1)
Output result:
2,"alex",}
set2={1,2,"alex",3,4}
print(set2.symmetric_difference(set1))
print(set2^set1)
5 Subsets and supersets (<,issubset, >,issuperset)
Child collection: (<, issubset)
set1={1,2,"alex",}
set2={1,2,"alex",3,4}
print(set1.issubset(set2))
print(set1<set2)
print result:
Superset: (>,issuperset)
set1={1,2,"alex",}
set2={1,2,"alex",3,4}
print(set2.issuperset(set1))
print(set2>set1)
print result
