Using a virtual environment for Project dev in Python is a good practice. venv is module that is available since Python 3.3. It can help us to manage the virtual environment in a simple way.

Manage virtual env#

Create a virtual env#

Normally, we create a virtual environment under the project root directory:

python -m venv paht/to/project-root/venv

The name we give to this virtual env is venv. Under the directory venv, there are different files and folders. Under my macOS system, it has the following files:

bin/        include/    lib/        pyvenv.cfg

Activate and de-activate#

To activate the virtual environment, run this command:

Then your shell prompt changes and tells you are now in the virtual environment. When the environment has been activated, the VIRTUAL_ENV env variable is set to the path of the environment.

To deactivate the virtual environment, just run deactivate.

ref:

• Python venv: https://docs.python.org/3/library/venv.html
• use venv in Linux: https://www.youtube.com/watch?v=Kg1Yvry_Ydk

Make jupyter work with virtual env#

First, we need to install the ipykernel package inside the virtual env:

Then we can generate a kernelspec for jupyter:

python -m ipykernel install --user --name <spec-name>
# output: Installed kernelspec venv in /Users/<your-user-name>/Library/Jupyter/kernels/<spec-name>

Now we can open the notebook:

jupyter notebook <your-notebook-name>.ipynb

In the opened browser tab for jupyter, we can click the Kernel menu and click change kernel to switch the kernel.

Kernelspec management#

To list your kernelspecs:

To remove the virtual env spec:

jupyter kernelspec remove <spec-name>

ref:

• https://janakiev.com/blog/jupyter-virtual-envs/#add-virtual-environment-to-jupyter-notebook
• ipython kernelspec: https://ipython.readthedocs.io/en/stable/install/kernel_install.html#kernels-for-different-environments