The difference between = = and is in Python

= = compares the values on both sides

Is compares the memory addresses on both sides to get memory addresses by ID ()

Small Data pools: The values we use are stored in small data pools for use by other data.

Small data pools are limited to numbers and strings:

Number of decimal pool ranges-5---256

String 1. Cannot have spaces;

2. The length cannot exceed 20 characters;

3. Cannot have special characters such as: @#$

1. ID () Get memory address

' Alex ' Print (ID (a))   # 36942544  memory address

2. = = Compare values on both sides

' Alex '  'Alex'print(a = = b  )=ten = tenprint (n= = [li1 = [n/a]print(= = = Li2) #True

3. Is compare memory address

　　3.1 List Dictionary tuple collection

#ListLi =[1,2,3]li2=[1,2,3]Print(Li isLI2)#False#Meta-groupTu = (A) TU1= (A)Print(TU isTU1)#False#DictionaryDic1 = {'name':'Alex'}dic= {'name':'Alex'}Print(Dic1 isDiC#False

Compare the above is#ListLi =[1,2,3]li2=[1,2,3]Print(Li = = li2)#True#Meta-groupTu = (A) TU1= (A)Print(Tu = = TU1)#True#DictionaryDic1 = {'name':'Alex'}dic= {'name':'Alex'}Print(Dic1 = = dic)#True

3.2 for the STR small data pool

String 1. Cannot have spaces;

2. The length cannot exceed 20 characters;

3. Cannot have special characters such as: @#$

A ='[email protected]'A1='[email protected]'Print(A isA1)#Falesa='a'*21b='a'*21Print(A isb#Falsea="AB"b="AB"Print(A isb#False But the result in Pycharm is true

3.3 Small Data pool for int

Number of decimal pool ranges-5---256

n =-6=-6  # out of range print is N1)  #False  =-5=-5print is N1)    #True

n = 257
N1 = 257
Print (n is N1)     #cmd中为False  displayed as true in Pycharm

　

The difference between = = and is in Python