Reassigning Variables

INTERACTIVE CHEAT SHEET

The Concept

When you write x = 20 after x = 10, Python does not change the 10. It creates a brand-new object 20 in a different memory location, then moves the label x to point at it. The old 10, now unlabelled, is automatically deleted by garbage collection. This is why reassignment is "moving the label," not "editing the box."

Key Points

Reassignment creates a new object in memory — it does not edit the old one.
The variable label detaches from the old value and points to the new one.
The old, unreferenced value is automatically garbage-collected by Python.

Core Concept Mastery • Python Visual Series Module