Dead Simple Method for Managing Python Virtual Environments

While there are many tools for managing python virtual environments, sometimes you just need something portable and dead simple.

The Method #

1. Use Python’s venv module directly
2. Create virtual environment directories in your project’s root – always call it env/.
3. (Optional) add an alias to make virtual environment activation more convenient.
4. Create, activate, deactivate, and delete environments to you hearts content.

The Commands You Need #

Disclaimer: These commands work on linux and mac, but will require modifications for Windows

1. Create a virtual environment folder in the current directory

python3 -m venv env

2. Activate a virtual environment in the current directory(manually)

$ source env/bin/activate

4. Deactivate the currently activated virtual environment

$ deactivate

3. (Optional) Activate a virtual environment in the current directory with an alias. See Configuration.

$ pyenv

Examples #

Creating a new virtual environment #

# navigate to a project root folder
cd ~/new-project

# create the environment
# Note: the python version invoked here will be the same version available in the virtual environment
python3 -m venv env

# activate the environment
pyenv

# or
source ./env/bin/activate

Moving Between Projects With Different Environments #

I have two projects – project1 and project2. I have already created an environment in the root of project1, activated it, and added some packages. Now, I need to move to project2, which has an entirely different set of dependencies, and activate the environment.

# Navigate to a project folder
cd ~/project1

# activate project 1 virtual environment
pyenv

# Do some work in project 1
...

# Move to project2 directory
cd ~/project2

# activate project2 virtual environment. (previously active environment will be deactivated first.)
pyenv

# Do some work in project 2
...

# Deactivate the current environment and move to the base environment
deactivate

Deleting an environment #

# navigate to project root
cd ~/project1

# delete the env folder
rm -rf env

Configuration #

Add an alias to your terminal configuration to make activate virtual environments more convenient. The example below will work for linux.

$ echo "alias pyenv=source ./env/bin/activate" >> ~/.bashrc
$ source ~/.bashrc

After adding this alias, typing the pyenv command will activate a virtual environment that is located in the current directoy and called env

Why Choose This Method? #

• No external package dependencies to install and configure
• Easier to keep track of which python environment should be associated with a given project
• Only requires a few commands
• The virtual environments are visible within the project and not hidden away
• Encourages creating new environments to isolate any project rather than reusing environments or just trashing your base environment

Why Not? #

• You aren’t interested in dealing with nitty-gritty details and want a set it and forget it solution.
• You enjoy constantly reconfiguring your environment when moving between computers or servers
• You have a large project that would benefit from a more robust tool such as poetry