Python id(object) - A guide to the Python id function, with examples

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.



The object argument can typically be a int , float , str , list , dict , tuple etc.

Code Sample

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

:rocket: Run Code

1 Like

Thanks! You show some ways to check the value it contains, but is it possible to use it for something else? Let’s take for instance your first example, can you retrieve the “a” using it’s identity using a kind of print(value_of(140454723286976))