Friday, June 27, 2025

Why and How to Use venv for Python AI Development


When you start developing AI applications with Python—be it for machine learning, deep learning, or deploying smart chatbots—you’ll often install many packages. Some are lightweight, like numpy or scikit-learn, while others like torch, transformers, or tensorflow can be heavy and version-sensitive.

This is where Python's built-in venv (virtual environment) becomes essential. In this blog post, we’ll walk through what venv is, why it's crucial for AI development, and how to properly structure your project so you avoid messy setups and environment conflicts.


🚀 What is venv and Why Should You Care?

A virtual environment in Python is a self-contained directory that holds a specific version of the Python interpreter and all the packages you install while that environment is active.

✅ Why use venv for AI projects?

  • Avoid version conflicts: You can use TensorFlow 2.15 in one project and PyTorch 2.2 in another without conflict.

  • Keep your system Python clean: Your system-wide Python won't get cluttered with dozens of packages.

  • Reproducibility: You can freeze the exact environment setup using requirements.txt for consistent deployments.

  • Isolation: Experiments won't interfere with each other. You can test different models or libraries without worry.


📁 Where Should I Keep My Project Folder?

This is a common beginner question:

Should my project folder be inside the virtual environment directory?

Short answer: No.
Long answer: Keep your project folder separate from the .venv folder. Here’s the best practice:


my-ai-project/

├── venv/                  ← your virtual environment

├── main.py                ← your code

├── data/                  ← datasets, models, etc.

├── notebooks/             ← Jupyter notebooks

├── requirements.txt       ← export of installed packages

└── README.md              ← documentation


You create the virtual environment inside the project folder, but keep it separate from your source code and data.


🛠️ Step-by-Step Guide to Using venv for AI Development

1. Create Your Project Folder


mkdir my-ai-project

cd my-ai-project


2. Create a Virtual Environment


python3 -m venv venv


  • This creates a venv folder inside your project folder.

  • You can name it something else (like .venv), but venv or .venv is a common convention.

3. Activate the Virtual Environment

On macOS/Linux:



source venv/bin/activate


On Windows (cmd):

venv\Scripts\activate


You’ll now see (venv) in your terminal prompt, showing the environment is active.

4. Install AI Packages


pip install numpy pandas scikit-learn matplotlib

pip install torch torchvision torchaudio

pip install transformers langchain


Or if you already have a requirements.txt file:

pip install -r requirements.txt


5. Start Coding!

Create your Python scripts or Jupyter notebooks and build your models confidently.


📦 Save Your Environment for Reuse

To allow others (or your future self) to recreate the environment:


pip freeze > requirements.txt


And later, in another machine or setup:


python3 -m venv venv

source venv/bin/activate

pip install -r requirements.txt



🧹 Bonus Tips

✅ Use .gitignore to Exclude venv

If you're using Git:

venv/

You should not upload the virtual environment to your GitHub repo. Just share your code and requirements.txt.

✅ Consider .venv for Cleaner Look

Naming your virtual environment .venv makes it a hidden folder (on Unix-based systems), which keeps things tidy:


python3 -m venv .venv


Your structure would then be:


my-ai-project/

├── .venv/

├── main.py

...


Many IDEs like VS Code also automatically detect .venv.


📚 When NOT to Use venv

If you're working with:

  • Docker containers (you manage environments via Dockerfile)

  • Conda environments (especially for GPU/CUDA setups)

  • Advanced tools like Poetry or Pipenv (for dependency management)

Then venv might not be your best fit. But for most beginner and intermediate AI projects, venv is simple, fast, and reliable.


💡 Final Thoughts

Using venv might seem like an extra step at first, but it’s a best practice that saves you countless hours of debugging and environment issues down the line. Especially in AI development where tools evolve rapidly, isolation is key.

Start every new AI project with:

python3 -m venv venv

source venv/bin/activate

...and thank yourself later.


If you're new to AI and Python, or want to learn how to build AI projects step-by-step, register for my Live course, and you can buy my recorded AI course here.  

Let me know in the comments: Do you use venv or prefer Conda? Why?


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