In this post I’ll cover setting up a virtual environment in Python 2.7 in preparation for working out a RESTful app in Flask.
Installation
So, I’ll assume you’re running a Debian flavor of Linux. You’ll need curl
, so if you don’t already have that, run the following from the command line:
sudo apt-get install curl
Then, using curl
, you can install pip
.
curl --silent --show-error --retry 5 https://bootstrap.pypa.io/get-pip.py | sudo python2.7
Then, using pip
, you can install virtualenv
.
sudo pip install virtualenv
Now, we’re good to go.
Creating a Virtual Environment
First create a directory to hold your virtual environments.
mkdir venvs
Next, create a virtual environment by specifying the root directory of that environment. By default, no site-packages
are installed.
virtualenv venvs/one
This creates a virtual environment in ./venvs/one/
. To activate this environment, use the command,
source venvs/one/bin/activate
This will change your command line to reflect that you are working in a virtual environment. To get out of the virtual environment, execute the following:
deactivate
Seeing What is Installed
To see what is installed in your virtual envrionment, use the yolk
utility. First install using apt-get
sudo apt-get install yolk
And then use the following from inside the virtual environment to see what you have installed.
yolk -l
are you using this for testing dependencies etc. when developing new installable python packages?
or what is the primary use of a python virtual environment? (less damage when py-script crashes inside this kind of ‘sandbox’?)