Python variable set

List is a combination that allows content to be duplicated

A tuple is a combination that allows content to be duplicated

Dict

Set is a combination that does not allow duplication of content, and the contents of the set are arbitrary, so they cannot be listed by index

Set creation:

#The first wayA=set (["a","b","C"])Print(a)#The second wayA=set () A.add ("a") A.add ("b")Print(a)#The Third Way, this way is not a={}a={"a","b","C"}Print(a)

#conversion of Set seta=["AWE","Weg","Dawqgg"]c=set (a)Print(c) B="Chenshuagege"D=Set (b)Print(d) Al=("233","34455") AW=set (AL)Print(AL)

Common methods of Set:

 #  difference means that content B in a is not, But this does not modify the value of a itself, but instead pays ret the  a={ 12  Span style= "COLOR: #800000" > ", "  14   ", "  234   " }b  ={ " 12   ", "     " }ret  = a.difference (b)  print  (ret) 

 #  difference_update means that content B in a is not, executed, Modifies the contents of a  a={ 12   ", "  14   ", "  234   " }b  ={ " 12   ", "     }a.difference_update (b)  print  (a) 

# Discard is the same as remove, but discard will not give an error, and remove will b={1,23}b.discard (1)print(b)

# take the intersection of the two b={1,23}a={23,5}ret=b.intersection (a)print(ret)

# take the intersection of the two, Intersection_update will change the content of B b={1,23}a={23,5}b.intersection_update (a) Print (b)

b={1,23}a={23,5}# returns False if A and B have a collection, and returns True ret= B.isdisjoint if there is no collection( A)print(ret)

b={1,23,5}a={23,5}#issuperset Description B is the father of a if it is output true if not output falseret=  B.issuperset (a)print(ret)

b={1,23,5}a={23,5}#B is the child of a, if it is true, output false ifit is not ret=  B.issubset (a)print(ret)

# pop () returns the item that was deleted a={"a","b","C  "}ret=a.pop ()print(a)

Python variable set