Many facets of Python’s Virtual Environments

This XKCD artwork is quite well know now.

However if you set up things right, its not a mess at all rather a charm to work with. We will see how easy is it with setting up environments.

We look at the following methods.

• Python venv
• Conda
• Poetry

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Python Virtual Environments with venv

Installing a specific python version using venv

sudo apt install python3.8-venv    

Create a virtual environment with venv.

python3 -m venv <envname>

Activate and deactivate the environment.

source <venv>/bin/acivate

# to deactivate
deactivate

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Conda

Download the version of conda you need as below and install.

wget https://repo.anaconda.com/miniconda/Miniconda3-py38_4.10.3-Linux-x86_64.sh

# install the above downloaded file
bash Miniconda3-<version>.sh

# remove the file once finished
rm Miniconda3-<version>.sh

Update conda

conda update conda

Creating new environments

conda create --name <env name>

# activate environment
conda activate <env name>

Adding packages to conda

conda install numpy

# Install env with different python version. 
conda create --name condaenv python=3.8.10

Adding packages form environments yaml.

A yaml file needs to be created first as described here

conda env create -f environments.yml

Now update environments based on yaml .

conda env update --file environments.yml

For all commands refer conda cheat sheet

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Poetry

This one is my personal favourite just becasue of its simplicity and how effective it is.

Install poetry with curl.

curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python -

If python is not found, replace it with python3. This could happen if you are using oh-my-zsh shell.

curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/get-poetry.py | python3 -

Initialise an environment. This automatically creates a .toml file in the directory with all packages.

poetry init

Once initialised, install or update if already installed.

poetry install

# in case of an update
poetry update

Adding packages to your project? Just do

poetry add <package name>

Build

Want to build the package as wheel?

poetry build

and you are good to go.

Pro Tip

1. *Do not install from pip. Always use the curl method as above.
2. Poetry installs envs in your .cache/ directory. This below command will install in your working directory if thats the way you work.

poetry config virtualenvs.in-project true