python == and is

'''
 == The equality of the test value
 is the consistency of the test object, that is, the same memory address
 '''
 l1=[ 1 ,( 'a' , 3 )]
l2=[ 1 ,( 'a' , 3 )]
 print (l1==l2)     #l1 and l2 are equal True
 print (l1 is l2)      #l1 and l2 are not the same object False
 print ( id (l1), id (l2))     #2272260557320 2272260585160

 s1= 'spam'
 s2= 'spam'
 print (s1==s2)     #s1 and s2 are equal True
 print (s1 is s2)      #s1 and s2 are the same object True
 print ( id (s1), id (s2))     #2658123313368 2658123313368