computer science class xi change the values once variable of that type has been created and assigned values variables whose values can be changed after they are created and assigned are called mutable variables whose values cannot be changed after they are created and assigned are called immutable when an attempt is made to update the value of an immutable variablethe old variable is destroyed and new variable is created by the same name in memory python data types can be classified into mutable and immutable as shown in figure figure classification of data types let us now see what happens when an attempt is made to update the value of variable num this statement will create an object with value and the object is referenced by the identifier num as shown in figure figure object and its identifier figure variables with same value have same identifier - num num the statement num num will make num refer to the value also being referred by num and stored at memory location numbersay sonum shares the referenced location with num as shown in figure