benefits.md

Benefits of Python Fire

Create CLIs in Python

It's dead simple. Simply write the functionality you want exposed at the command line as a function / module / class, and then call Fire. With this addition of a single-line call to Fire, your CLI is ready to go.

Develop and debug Python code

When you're writing a Python library, you probably want to try it out as you go. You could write a main method to check the functionality you're interested in, but then you have to change the main method with every new experiment you're interested in testing, and constantly updating the main method is a hassle. You could also open an IPython REPL and import your library there and test it, but then you have to deal with reloading your imports every time you change something.

If you simply call Fire in your library, then you can run all of it's functionality from the command line without having to keep making changes to a main method. And if you use the --interactive flag to enter an IPython REPL then you don't need to load the imports or create your variables; they'll already be ready for use as soon as you start the REPL.

Explore existing code; turn other people's code into a CLI

You can take an existing module, maybe even one that you don't have access to the source code for, and call Fire on it. This lets you easily see what functionality this code exposes, without you having to read through all the code.

This technique can be a very simple way to create very powerful CLIs. Call Fire on the difflib library and you get a powerful diffing tool. Call Fire on the Python Imaging Library (PIL) module and you get a powerful image manipulation command line tool, very similar in nature to ImageMagick.

The auto-generated help strings that Fire provides when you run a Fire CLI allow you to see all the functionality these modules provide in a concise manner.

Transition between Bash and Python

Using Fire lets you call Python directly from Bash. So you can mix your Python functions with the unix tools you know and love, like grep, xargs, wc, etc.

Additionally since writing CLIs in Python requires only a single call to Fire, it is now easy to write even one-off scripts that would previously have been in Bash, in Python.

Explore code in a Python REPL

When you use the --interactive flag to enter an IPython REPL, it starts with variables and modules already defined for you. You don't need to waste time importing the modules you care about or defining the variables you're going to use, since Fire has already done so for you.