I Keep Forgetting How to Create Python Virtual Environments

Every few weeks, I run into the same problem.

I open a new Python project, stare at my terminal, and think...

"Wait... was it python -m venv .venv or python3 -m venv venv?"

Instead of searching Google or Stack Overflow for the hundredth time, I figured I'd write everything down here.

This post is mainly for future me, because I somehow forget these commands every few weeks.

But if you found this through Google or happened to stumble across my blog, welcome! Hopefully this saves you a few minutes too.

What Is a Virtual Environment?

A virtual environment (or venv) is an isolated Python environment for a project.

Instead of installing every package globally on your computer, each project gets its own set of dependencies.

For example:

Project A might use:

Flask 3.1
Requests 2.32

Project B might use:

Django 5
FastAPI
SQLAlchemy

Without virtual environments, these projects could end up conflicting with one another.

Keeping each project's dependencies separate makes life much easier.

Where Should I Create My Project?

One thing that confused me when I first started learning Python was where I was actually supposed to create my projects.

My Python installation lives on my C: drive, but that doesn't mean every Python project has to live there too.

Personally, I prefer keeping all my projects on another drive, such as D:. That way I don't flood my operating system drive with dozens of repositories, virtual environments and downloaded packages.

My folder structure usually looks something like this:

D:\
└── Projects
    ├── Flask-App
    ├── Discord-Bot
    ├── Data-Analysis
    └── Random-Scripts

Then I simply navigate to whichever project I'm working on.

cd D:\Projects\Flask-App

The important thing to understand is this:

Your Python interpreter can be installed on C: while your project and virtual environment live on D: (or any other drive).

The venv command simply uses your installed Python to create a self-contained environment inside your current project folder.

So don't worry if your Python installation and your projects aren't on the same drive—they don't need to be.

Step 1: Create a Project Folder

If you haven't already created one:

mkdir my-project
cd my-project

Step 2: Create the Virtual Environment

I usually name mine .venv since many editors recognise it automatically.

python -m venv .venv

If your system uses python3, run:

python3 -m venv .venv

After running the command, your folder should look something like this:

my-project/
│
├── .venv/

Step 3: Activate It

Windows (Command Prompt)

.venv\Scripts\activate

Windows (PowerShell)

.venv\Scripts\Activate.ps1

If PowerShell blocks the script, you can temporarily allow local scripts for your current session:

Set-ExecutionPolicy -Scope Process RemoteSigned

Then run the activation command again.

macOS / Linux

source .venv/bin/activate

Once activated, your terminal usually changes to something like this:

(.venv) D:\Projects\Flask-App>

That's how you know you're inside the virtual environment.

Step 4: Install Packages

Now install whatever your project needs.

For example:

pip install flask

pip install requests

You can check what's installed using:

pip list

Step 5: Save Your Dependencies

Once you've installed everything you need, save the dependency list.

pip freeze > requirements.txt

Your requirements.txt might look like this:

Flask==3.1.0
requests==2.32.0
pandas==2.3.1

This makes it easy to recreate the environment later.

Step 6: Install Dependencies on Another Machine

If someone else clones your project—or if future you returns to it six months later—all that's needed is:

pip install -r requirements.txt

Python will install every package listed in the file.

Step 7: Deactivate the Environment

When you're finished working:

deactivate

That's it.

Don't Commit Your Virtual Environment

Your virtual environment can easily grow to hundreds of megabytes.

Instead of uploading it to GitHub, add it to your .gitignore file.

.venv/

Only commit your source code and your requirements.txt.

Anyone can recreate the environment by running the install command.

My Usual Workflow

Whenever I start a new Python project, I pretty much follow these commands.

mkdir my-project
cd my-project

python -m venv .venv

# Windows
.venv\Scripts\activate

# macOS/Linux
source .venv/bin/activate

pip install <packages>

pip freeze > requirements.txt

It's honestly about 95% of what I ever need.

Bonus: Check Which Python You're Using

Sometimes you have multiple Python installations on your computer.

To see which one is currently being used:

Windows

where python

macOS / Linux

which python

You can also check the version directly:

python --version

Final Thoughts

Virtual environments aren't difficult.

They're just one of those things I use often enough to know they exist, but not often enough to remember the commands.

So this post is mostly for future me—and anyone else who somehow ends up here after forgetting the exact same thing.

If you're reading this because you searched "how to create a Python virtual environment" for the hundredth time...

Welcome to the club.

Hopefully this post saves both of us from opening Stack Overflow again.