When a Python program runs, it goes through compilation, memory allocation, and execution phases, all managed automatically by the Python interpreter (CPython for most users).

1. Compilation to Bytecode Python is an interpreted language, but before execution, the .py source code is compiled into bytecode (.pyc files in __pycache__). This bytecode is a lower-level, platform-independent representation that the Python Virtual Machine (PVM) executes.

2. Memory Allocation Python uses two main memory areas:

• Stack Memory – Stores function call frames, local variables, and references to objects. Freed automatically when a function exits.

• Heap Memory – Stores actual objects (lists, dicts, strings, etc.). References to these objects are kept in the stack. Objects in the heap can outlive the function that created them.

Example:

3. Memory Management Mechanisms

• Reference Counting – Each object tracks how many references point to it. When the count hits zero, memory is freed.

• Garbage Collection – Handles cyclic references that reference counting alone can’t clean up.

• Object Interning – Small immutable objects (e.g., integers -5 to 256) are reused to save memory.