This content originally appeared on DEV Community and was authored by Prakash Vinukonda
Before starting this blog. I would like you all to install two things in your computer from any browser:
- Python from https://www.python.org/downloads/
- VS code from https://code.visualstudio.com/download
- PIP – Installed automatically with Python as part of python installation. You can check the PIP using the command:
pip --version
Why do we need to install python?
Python (The Interpreter): Python is the brain behind the scenes. It reads your .py files and executes the code line by line.
Without Python installed, your computer won’t understand the instructions you write in Python code.
Why do we need VS Code (The Code Editor)?
Visual Studio Code (VS Code) is where you write your Python programs. It’s a powerful, lightweight text editor that makes writing code much easier with:
- Syntax highlighting (colorful code)
- Auto-complete suggestions
- Debugging tools
- Extensions (like Python formatter, linting, and more)
Understanding the execution of python program
The execution of python program involves two steps:
- Compilation
- Interpreter
Compilation
The process of converting a Python program into bytecode is known as compilation.
- Bytecode consists of a fixed set of instructions that handle arithmetic, comparison, and memory operations. Since it is platform-independent, it can run on any operating system or hardware.
- These bytecode instructions are stored in a .pyc file, which is usually created internally by Python. However, you can generate and view it explicitly using the commands:
python -m py_compile file_name.py
python -m dis file_name.py
Interpreter
The interpreter is responsible for converting Python bytecode (.pyc) into machine code (binary 0s and 1s) so that the CPU can execute the program.
- It reads the bytecode and translates it into machine-level instructions.
- This task is handled by the Python Virtual Machine (PVM), which ensures the program runs on the underlying hardware.
Here’s a simple diagram that illustrates the execution flow
To Summarize, When you write a Python program in a .py file, it’s in human-readable form. Once executed (using the command python file_name.py from terminal), Python compiles it into bytecode (.pyc), which is a lower-level set of instructions meant for the Python Virtual Machine (PVM). The PVM then translates this bytecode into machine code (binary instructions: 0s and 1s), which the computer’s CPU can directly understand and execute. At this stage, your program interacts with the hardware to perform tasks like displaying output, calculations, or saving files.
In the next blog, we’ll dive into Python keywords and built-in functions.
Thanks for reading! Catch you in the next one — happy learning! ❤️
This content originally appeared on DEV Community and was authored by Prakash Vinukonda
Prakash Vinukonda | Sciencx (2025-08-16T13:05:50+00:00) Python Behind the Scenes – Understanding Code Execution Flow. Retrieved from https://www.scien.cx/2025/08/16/python-behind-the-scenes-understanding-code-execution-flow/
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