Identity

Definition

Identity in Python refers to the uniqueness of an object. It is determined by the object's memory address, which can be checked using the id() function.

5 Must Know Facts For Your Next Test

1. Two objects with the same value may have different identities if they are stored at different memory addresses.
2. The 'is' operator checks if two variables reference the same object (i.e., have the same identity).
3. The id() function returns a unique identifier for an object, which is its memory address.
4. Immutable objects like integers, strings, and tuples with the same value often share the same identity due to interning.
5. Mutable objects like lists and dictionaries always have unique identities unless explicitly assigned.

Review Questions

• How do you check if two variables reference the same object in Python?
• What does the id() function return when called on an object?
• Why might two mutable objects with the same content not share the same identity?

Related terms

Variable:

A symbolic name associated with a value and whose associated value may be changed.

Mutable Object: An object whose state or contents can be modified after it is created.

'is' Operator: A comparison operator that checks if two variables refer to the same object in memory.