About the collation of the Python collection (set)

Collection

1. Composition of different elements
2. Disordered
3. The elements in the collection must be immutable types (numbers, strings, tuples)

Definition of the collection:

s = {1,2,3,3,4}

s = {' Hello '}

Transformations can only be converted if the object is iterated

Set method

-add #将对象添加到集合中

S ={1,2,3,4,5,6}s.add ("s") S.add ('3') S.add (3) print (s) #结果: {1,2,3,4,5,6,'s','3'}

-clear

s ={1,2,3,4,5,6}s.clear () print (s) #结果:  Set()

-copy

s = {1,2,3,4,5,6= s.copy () print (S1) #结果: { 1 2 3 4 5 6}

-pop #随机删除

-remove #指定删除

s = {'SB', 1,2,3,4,5,6}s.pop ()Print(s)#Random DeleteS.remove ('SB')Print(s)#Specify Delete#s.remove (' helo ') #删除元素不存在, will errorS.discard ('SSBB')#delete element, not present or error-guaranteed#results: {2, 3, 4, 5, 6, ' SB '}#{2, 3, 4, 5, 6}

General methods for common items

Python_1 =['LCG','SZW','ZJW']linux_1= ['LCG','SZW']python_and_linux= [] forP_nameinchpython_1:ifP_nameinchlinux_1:python_and_linux.append (p_name)Print(Python_and_linux)#result: [' LCG ', ' szw ']

#in a collection of waysPython_1 =['LCG','SZW','ZJW']linux_1= ['LCG','SZW','SB']p_s= Set (python_1)#Convert to Collectionl_s =Set (linux_1)Print(p_s)

1 Print(l_s)2 Print(P_s.intersection (l_s))#ask for intersection3 Print(p_s&l_s)4 5 #Seek and set6 Print(P_s.union (l_s))7 Print(p_s|l_s)8 9 #Finding the difference setTen Print("Difference Set", p_s-l_s) One Print("Difference Set", l_s-p_s) A Print(P_s.difference (l_s)) -  -  the " "Results: - {' LCG ', ' zjw ', ' SZW '} - {' LCG ', ' sb ', ' SZW '} - {' LCG ', ' SZW '} + {' LCG ', ' SZW '} - {' LCG ', ' zjw ', ' sb ', ' SZW '} + {' LCG ', ' zjw ', ' sb ', ' SZW '} A differential set {' ZJW '} at difference set {' SB '} - {' ZJW '}" "

View Code

1Python_1 =['LCG','SZW','ZJW']2Linux_1 = ['LCG','SZW','SB']3p_s = Set (python_1)#Convert to Collection4l_s =Set (linux_1)5 #Cross complement set6 #Cross complement set7 Print(P_s.symmetric_difference (l_s))8 Print(p_s^l_s)9 Results:Ten{'SB','ZJW'} One{'SB','ZJW'}

Cross complement set

1-differnece_update2Python_1 =['LCG','SZW','ZJW']3Linux_1 = ['LCG','SZW','SB']4p_s =Set (python_1)5l_s =Set (linux_1)6 Print(p_s-l_s)7 Print(p_s)8P_s.difference_update (l_s)#update the differential set, the updated data is9 Print(p_s)Ten Results: One{'ZJW'} A{'LCG','ZJW','SZW'} -{'ZJW'}

Update differential Set

S1 = {1,2,3,4= {5,6,7}print(s1.isdisjoint (S2))# Determines if there is no intersection and returns true if there is no intersection  # Result: True

1 s1 = {2 s2}3print(s1.issubset (S2))# whether a subset is in the case 4 # Result: True

-judge S1 to be a subset of S2

1 Print (S2.issuperset (S1)) # whether it is a parent set 2 # Result: True

S1 = {$}

1 # go heavy, without regard to the order of the case 2 names = ["Alex","Alex",'Wupeiqi  ']3 names = list (set (names))4print( Names)5# results: [' Alex ', ' Wupeiqi ']

Frozenset () frozen set, i.e. immutable set

= {}s1.update (s2)# updates the data in the collection and can pass in an iterative object      print(S1)# Result: {1, 2, 3}

About the collation of the Python collection (set)