Fabric is favored among Python web developers for its simplicity and ease of use. It expects a file named fabfile.py that defines all the actions (for deployment or otherwise) in your project. Each of these actions can be a local or remote shell command. The remote host is connected via SSH.
The key strength of Fabric is its ability to run commands on a set of remote hosts. For instance, you can define a web group that contains the hostnames of all web servers in production.
You can run a Fabric action only against these web servers by specifying the web group name on the command line.
To illustrate the tasks involved in deploying a site using Fabric, let's take a look at a typical deployment scenario.