11 February 2025

How Python Works : How Python executes code (Interpreter vs. Compiler)

Python is an interpreted language, meaning its code is executed line by lline rather than being compiled into machine code beforehand. Let's understand the difference between an interpreted and a compiler and how python processes code.

- Interpreter vs. Compiler

Feature : Execution 
Interpreter (Python) : Line-by-line execution 
Compiler(C, Java, etc.) : Translated entire code before execution

Feature : Speed 
Interpreter (Python) : Slower (executes each line separately)
Compiler(C, Java, etc.) : Faster (precompiled machine code runs directly)

Feature : Error Handling 
Interpreter (Python) : Stops at the first error 
Compiler(C, Java, etc.) : Detects all errors before execution

Feature : Flexibility
Interpreter (Python) : More flexible, allows interactive execution 
Compiler(C, Java, etc.) : Less flexible, requires full compilation

- Python's Execution Process
1. Source Code (.py file) - The python script is written in human-readable form.

2. Compilation to Bytecode (.pyc file) - Python converts the source code into an intermediate bytecode (not machine code). This step is hidden from the user and speeds up execution.

3. Execution by Python Virtual Machine (PVM) -  The bytecode is processed by the Python Interpreter, which translates it into machine code line by line and runs it.

Why Python Uses an Interopreter?
- Platform Independence - Bytecode runs on any system with Python installed.
- Ease of Debugging - Ideal for Interactive development and scripting.

Though Python is an interpreted language, tools like PyPy(JIT Compiler) and Cython can be improve performance by introducing compilation-like optimizations.

Would you lilke a comparison with other programming languages?