id() is a built-in function in Python 3, which returns the identity of an object. The identity is a unique integer for that object during its lifetime. This is also the address of the object in memory.
object argument can typically be a
a = 2 print(id(a)) #=> 140454723286976 (Values returned by id() might be different for different users) b = 3 print(id(b)) #=> 140454723287008 c = 2 print(id(c)) #=> 140454723286976 (This is same as id(a) since they both contain the same value and hence have same memory address) print(id(a) == id(b)) #=> False (since a and b have different values stored in them) print(id(a) == id(c)) #=> True (since a and c have same values stored in them) d = 1.1 e = 1.1 print(id(d) == id(e)) #=> True (since d and e have same values stored in them) str1 = 'hello' str2 = 'hello' print(id(str1) == id(str2)) #=> True (since str1 and str2 have same values stored in them) # For complex objects like lists, tuples, dictionaries etc. id() would give a unique integer even if the content of those containers is same. tup1 = (1,1) tup2 = (1,1) print(id(tup1) == id(tup2)) #=> False