Description

In a recent hackathon project, our team faced issues when we couldn't replicate each other's Python environments — mainly because we didn’t use virtual environments and forgot to track installed libraries. Here's how you can avoid that disaster, and a simple bash script to automate updating your requirements.txt file!

How We Messed Up in a Hackathon

A few weeks ago, I participated in a hackathon.
We worked hard, divided modules, coded all night.
But when it was time to merge and test the project — boom, environment errors everywhere.

Why?

Some team members didn’t use a virtual environment (venv).
We installed libraries manually without keeping track.
We forgot to update requirements.txt.
Replicating the environment across machines became a nightmare.

Lesson learned:
👉 Not tracking dependencies properly kills collaboration.

Why You Must Track Dependencies

When you install a library like requests, pip also installs its dependencies (urllib3, certifi, etc.).
If you don't track them, reproducing your project later becomes impossible.

Keeping an updated requirements.txt ensures:

Others can recreate your environment.
Deployment on production servers is smooth.

The Solution: Automate It

Instead of manually adding libraries to requirements.txt,
let’s automate it with a simple Bash script.

This script:

Installs your new libraries.
Automatically updates requirements.txt.
Works on both Windows (Git Bash/WSL) and Linux/Mac.

# create a virtual environment
python -m venv .venv
source .venv/Scripts/activate

Save this as pip-requirements-update.sh:

pip freeze > before.txt
pip install "$@"
pip freeze > after.txt
diff before.txt after.txt | grep ">" | sed 's/> //' >> requirements.txt

sort -u requirements.txt -o requirements.txt
rm before.txt after.txt

echo "✅ Installation complete and requirements.txt updated!"

Situation	Command
Git Bash	`source .venv/Scripts/activate`
Windows PowerShell	`.venv\Scripts\Activate.ps1`
Windows CMD	`.venv\Scripts\activate.bat`
Linux/macOS Bash	`source .venv/bin/activate`

📋 How to Use

Save the script in your project root.
Make it executable:
```
 chmod +x pip-requirements-update.sh
```

Install new packages like this:

 ./pip-requirements-update.sh flask requests

⚡ Why This Script Gives You an Edge

Traditional Way	Using This Bash Script
Install package manually with `pip install` and remember to freeze later.	Install + freeze automatically in one command.
Risk of forgetting to update `requirements.txt`.	Always up-to-date `requirements.txt`.
Higher chance of human error and missed dependencies.	Zero manual errors, complete tracking.
Time wasted in manual maintenance.	Fast, one-click maintenance.
Unprofessional repos.	Clean, production-ready repos.

🚀Never Lose Track of Python Dependencies Again: Automating requirements.txt Updates