Setting up Python Development Environments
— Yash Agarwal4 minutesRecently I was searching for Python projects on Github for contribution. Every single project I found, had a thing common among them. In every project’s contribution guide, it was asked to set up the virtual environment for the project. What the heck is this virtual environment and how does it work?
As a beginner to open source projects, the problem I faced, in the beginning, was how to set up the development environments for the projects I was looking at. I searched the Internet, I found some articles, but they were not complete. So I decided to write this guide, which will be useful for me in future also.
Python uses pip
for package management.
Installing pip #
pip
depends on setuptools library, which is in official Ubuntu repositories. To install it for python2 -
sudo apt-get install python-setuptools
Then install pip
using -
sudo apt-get install python-pip
and for python3 -
sudo apt-get install python3-setuptools
Then install pip
using -
sudo apt-get install python3-pip
It should install pip
on your system for both python versions. pip
is very easy to use. It will take care of every single package you may require for your project.
Installing a package using pip #
# it will search and install [package]
pip install [package]
pip install django
pip3
.pip
can be used to install a specific version of package also.
# it will search and install [package] with [version]
pip install [package]==[version]
pip install django==1.6.5
Uninstalling a package using pip #
# it will search and uninstall [package]
pip uninstall [package]
pip uninstall django
upgrading a package using pip #
# it will upgrade [package] to latest version
pip install --upgrade [package]
pip install --upgrade django
Creating list of all packages with pip #
It is one of most used and most useful feature of pip
. It allows you to make a list of all the dependencies of your project.
# it will output the file to current directory
pip freeze > [file_name.txt]
All these commands above will install the packages globally. But that’s not what is desired. virtualenv
comes to our rescue here.
Virtualenv #
virtualenv
solves a very particular problem; it allows multiple python projects that have different and often conflicting dependencies, to coexist on the same system.
virtualenv
solves this problem by creating different isolated development environments for your projects. An environment is a folder which contains everything; your project needs to work properly.
Installing virtualenv #
By default, if you install virtualenv
using pip
, it will use system’s default python to create virtual environments. To overcome this problem, we will install virtualenv
using ubuntu package manager.
sudo apt-get install python-virtualenv
Installing virtualenvwrapper #
virtualenvwrapper
provides some set of commands which makes working with virtual environments much easier.
To install it -
sudo pip install virtualenvwrapper
pip
, virtualenv
and virtualenvwrapper
are the only packages which you will need to install globally. All other per project packages will be installed in respective virtual environments.
virtualenvwrapper
also places all your virtual environments in one place. It makes working with projects very easy.
Now open your .bashrc
and add these two lines to the end -
# All your projects will be saved in python-dev folder
export PROJECT_HOME=~/python-dev
# ~/python-dev/virtualenvs will contains python interpreters for each project.
export WORKON_HOME=~/python-dev/virtualenvs
# source the virtualenvwrapper script
source /usr/local/bin/virtualenvwrapper.sh
You can change python-dev
to any name you wish. Your virtual environments will be created at that location.
Now restart your terminal to source the .bashrc
or use -
source .bashrc
Basic Usage #
Create a virtual environment -
mkvirtualenv myproject
It will create myproject
folder in the python-dev directory. To activate this project -
workon myproject
Alternatively you can create project using mkproject
command. It will create a virtual environment as well as a project directory in the $PROJECT_HOME
, which is cd
-ed into when you workon
myproject.
Don’t forget to deactivate current project when you switch between different projects.
To deactivate a project -
deactivate
To delete a virtual environment -
rmvirtualenv myproject
List all environments -
lsvirtualenv
it will also list all virtual environments -
workon
Please refer to virtualenvwrapper documentation for full list of virtualenvwrapper commands.
virtualenvwrapper also provides the tab-completion feature which is very handy when you have a lot of projects to work with.
That’s it. Hope you liked the post. 😄