Collection set
1. The collection of different elements, unordered collection is a group of arrayed elements of the collection must be immutable
- the definition of a collection
The first:
i = {1,2,3,4 }
print (type (i), i)
operation result:
<class 'set'> {1, 2, 3, 4} Process finished with exit code 0
The second:
jh = set('hello') print(type(jh),jh)
operation result:
<class 'set'> {'e', 'o', 'h', 'l'} Process finished with exit code 0
- Add elements
jh = {1,2,3,4}
jh.add("nihao")
print(jh)
{1, 2, 3, 4, 'nihao'}
Process finished with exit code 0
-delete
* .Clear Clear collection
* .Pop randomly deleted
i = {1,2,3,4 }
Jkpop ()
print (i)
operation result:
{2, 3, 4}
Process finished with exit code 0
* .Remove delete the specified element (if the element is not specified, it will error)
jh = {1,2,3,4 }
jh.remove ( 4 )
print (jh)
operation result:
{1, 2, 3}
Process finished with exit code 0
* .Discard delete the specified element (if the element is not specified, no error)
- Intersection &
math = {'xm','xh','xg'}
english ={'xm','xh'}
print(math.intersection(english))
operation result:
{'xh', 'xm'}
Process finished with exit code 0
- union |
math = {'xm','xh','xg','xx'}
english ={'xm','xh','dm','john'}
print(math.union(english))
operation result:
{'xg', 'dm', 'john', 'xm', 'xx', 'xh'}
Process finished with exit code 0
- difference set (two sets may be subtracted)
math = {'xm','xh','xg','xx'}
english ={'xm','xh','dm','john'}
print(math.difference(english))
print(english.difference(math))
operation result:
{'xg', 'xx'}
{'dm', 'john'}
Process finished with exit code 0