In Python, id() function is a built-in function that returns the unique identifier of an object. The identifier is an integer, which represents the memory address of the object. The id() function is commonly used to check if two variables or objects refer to the same memory location.
Python id() Function Syntax
Syntax: id(object)
Return: a unique integer for a given object
How id() Function Work?
In this example, we can see the function accepts a single parameter and is used to return the identity of an object. This identity has to be unique and constant for this object during its lifetime. Two objects with non-overlapping lifetimes may have the same id() value. If we relate this to C, they are the memory address, here in Python it is the unique ID. This function is generally used internally in Python.
x = 42
y = x
z = 42
print ( id (x))
print ( id (y)) # (same as x)
print ( id (z)) # (same as x and y)
|
140642115230496 140642115230496 140642115230496
Python id() function Examples
Below are the ways with which we can use id() function in Python:
- Inbuilt DataTypes
- Custom Object
- With Sets
- With Tuples
Python id() for Inbuilt DataTypes
In this example, we are printing the id of multiple datatypes like strings and lists to get object identity in Python
# This program shows various identities str1 = "geek"
print ( id (str1))
str2 = "geek"
print ( id (str2))
# This will return True print ( id (str1) = = id (str2))
# Use in Lists list1 = [ "aakash" , "priya" , "abdul" ]
print ( id (list1[ 0 ]))
print ( id (list1[ 2 ]))
# This returns false print ( id (list1[ 0 ]) = = id (list1[ 2 ]))
|
140161148229168 140161148229168 True 140161147809712 140161147916400 False
Python id() for custom object
In this example, we are creating the Python class and we are creating two Python class objects and checking their ids to get object identity in Python.
class MyClass:
pass
# Create two instances of MyClass obj1 = MyClass()
obj2 = MyClass()
# Print the id of each object print ( id (obj1))
print ( id (obj2))
|
140225741483792 140225741483856
Python id() with Sets
In this example, we are using the id function on sets to get object identity in Python.
set1 = { 1 , 2 , 3 }
set2 = { 3 , 2 , 1 }
set3 = { 1 , 2 , 3 }
print ( id (set1)) # Output: <id1>
print ( id (set2)) # Output: <id2>
print ( id (set3)) # Output: <id3>
|
140483509094352 140483509093872 140483509095792
Python id() with Tuples
In this example, we are using the id function on tuples to get object identity in Python.
tuple1 = ( 1 , 2 , 3 )
tuple2 = ( 3 , 2 , 1 )
tuple3 = ( 1 , 2 , 3 )
print ( id (tuple1)) # Output: <id1>
print ( id (tuple2)) # Output: <id2>
print ( id (tuple3)) # Output: <id3>
|
140544960491680 140544960107456 140544960491680