When and How to Use the `id()` Function in Python?

Understanding the id() Function in Python

The id() function in Python is used to retrieve the unique identifier for an object. This identifier is an integer that remains constant throughout the lifetime of the object and guarantees uniqueness.

Interpreting the Returned Value

The value returned by id() is not necessarily the object's memory address. In CPython, it is indeed the memory address, but in other implementations, it may be an arbitrary integer representing the object's identity.

Example: Identity of List Elements

In the example provided, id() is called on elements of a list. The results do not correspond directly to the data type's size because a list is not an array. Instead, it stores references to objects, and the id() values represent the identity of those references.

When to Use id()

The use of id() in practice is limited. It can be helpful for debugging purposes, such as verifying that two variables refer to the same object. However, the is operator is the preferred method for comparing object identity.

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