Introduction to Python & Setup

Why Python?

Python is the most versatile language in the industry: it powers Instagram’s backend, Netflix’s recommendation pipelines, NASA’s data analysis, and almost every AI lab on the planet. Its superpower is readability — Python code looks close to pseudocode, which makes it fast to write, easy to review, and beginner-friendly without being a toy.

• Web — Django, FastAPI, Flask
• Data & AI — pandas, PyTorch, scikit-learn
• Automation — scripts, scraping, DevOps tooling

Install Python

Install Python 3.12+ from python.org or your package manager, then verify:

python3 --version
# Python 3.12.x

Two Ways to Run Python

1. The REPL — an interactive prompt, perfect for experiments:

python3
>>> 2 + 2
4
>>> "coding" + " india"
'coding india'
>>> exit()

2. Script files — real programs live in .py files:

# hello.py
print("Hello from Coding India")

python3 hello.py

How Python Reads Your Code

Python is interpreted (no compile step — edit and run) and dynamically typed (variables don’t declare types; values carry them). Most importantly, Python uses indentation instead of braces to define blocks:

if 5 > 3:
    print("five wins")      # 4 spaces of indentation = inside the if
print("always runs")        # back at the left margin = outside

Consistent 4-space indentation isn’t a style preference in Python — it’s syntax. Configure your editor now and never think about it again.

Your Editor

VS Code with the official Python extension is the standard choice: autocomplete, linting, debugging, and notebook support out of the box. Enable “Format on Save” with black or ruff and your code stays clean automatically.