Skip to content

Virtual Environment Guide

Jump to bottom
Parth Verma edited this page Jan 3, 2020 · 2 revisions

Virtual Environment Setup

Virtual environments are independent groups of Python libraries, one for each project. Packages installed for one project will not affect other projects or the operating system’s packages.

Python 3 comes bundled with the venv module to create virtual environments.

Install pyenv

To manage multiple versions of python the most popular app is pyenv:

Install dependencies

sudo apt-get install -y make build-essential libssl-dev zlib1g-dev \
libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev \
libncursesw5-dev xz-utils tk-dev libffi-dev liblzma-dev python-openssl

Install pyenv

  1. curl https://pyenv.run | bash

    you should see a message like

WARNING: seems you still have not added 'pyenv' to the load path.

# Load pyenv automatically by adding
# the following to ~/.bashrc:

export PATH="$HOME/.pyenv/bin:$PATH"
eval "$(pyenv init -)"
eval "$(pyenv virtualenv-init -)"
2. `nano ~/.bashrc`
3. paste the message into the file
4. restart the shell

P.S if you're using other shell like zsh replace the bash and bashrc accordingly

Install python version

pyenv install <version>

The new python version should be installed in the directory ~/.pyenv/versions/<version>

Create an environment

One of the most popular virtual environment manager is virtualenv

Install virtualenv

Install pip
sudo apt-get install python3-pip
Install virtualenv using pip3

sudo pip3 install virtualenv

Create virtual environment

  1. It's recommended to create the virtual environment in their respective folder

  2. virtualenv -p <python file location> <virtual environment name>

    ex:

    ​ virtualenv -p ~/.pyenv/versions/3.7.3/bin/python venv

Activate the environment

Before you work on your project, activate the corresponding environment:

source venv/bin/activate

Your terminal will change to show the name of the activated environment.

Deactivate the environment

deactivate

Create requirements.txt

You need requirements.txt file to keep track of all the installed packages in your app to create it, follow the following steps

  1. activate the virtual environment
  2. pip freeze This command shows you all the packages in your virtual environment
  3. pip freeze > requirements.txtredirects all the package names with their versions into the requirements.txt file
Clone this wiki locally