Collection
- Composition of different elements
- Disordered
- 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)