Python - lesson 4 | HackIndia Skills

Key point

One project, one env

A virtual environment is a local Python setup for one project. It keeps your packages inside the project folder, not mixed with your system Python.

This matters when your hackathon teammate clones your repo. They should install the same packages you used, not guess from your laptop.

Why it matters

Without an env, you may install packages globally. Later, one project needs requests 2.x and another needs a different version. Your scripts start failing in confusing ways.

A clean env also makes your repo look internship-ready. It shows you know how to make code runnable on another machine.

Your to-do

Create the env

Do each one yourself, then tap it to tick it off. The ticks are only a checklist for you: they are not marked or scored.

Open a terminal in your project folder.
Run the Python venv command for your system.
Activate the environment before installing packages.
Check that python and pip now point to the env.

0 of 4 done

# macOS / Linux
python3 -m venv .venv
source .venv/bin/activate
which python
which pip

# Windows PowerShell
py -m venv .venv
.venv\Scripts\Activate.ps1
where python
where pip

Example

Install one package

After activation, install packages normally. They go into .venv, not your global Python.

For this track, requests is a common package you will use later when calling APIs. Install it now only if your current script needs it.

pip install requests
python -c "import requests; print(requests.__version__)"

Your to-do

Freeze dependencies

Do each one yourself, then tap it to tick it off. The ticks are only a checklist for you: they are not marked or scored.

Install only the packages your project uses.
Run pip freeze after your script works.
Save the output into requirements.txt.
Commit requirements.txt to GitHub.
Do not commit the .venv folder.

0 of 5 done

pip freeze > requirements.txt

# See what got saved
cat requirements.txt   # macOS / Linux
type requirements.txt  # Windows

Common mistake

Do not upload .venv

The .venv folder can be large and machine-specific. Your repo should contain instructions and requirements.txt, not the installed environment itself.

Add .venv to .gitignore so Git does not track it. If you already added it by mistake, remove it from Git tracking.

.venv/
__pycache__/
*.pyc

Tip

Rebuild test

Before submitting, test your setup like a teammate would. This catches missing packages and unclear steps.

If you use AI to write setup instructions, ask it for Windows and macOS/Linux commands. Then check every command yourself in a fresh terminal.

deactivate
rm -rf .venv        # macOS / Linux
# On Windows, delete the .venv folder from File Explorer

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python your_script.py

Your to-do

Do this now

Do each one yourself, then tap it to tick it off. The ticks are only a checklist for you: they are not marked or scored.

Create a .venv folder inside your Python tool repo.
Activate it and install one package your script needs, if any.
Generate requirements.txt with pip freeze.
Add .venv/ to .gitignore.
Run your script once from the activated env.

0 of 5 done

Use virtual environments cleanly

One project, one env

Why it matters

Create the env

Install one package

Freeze dependencies

Do not upload .venv

Rebuild test

Do this now

Quick check