Python Fire is a library for automatically generating command line interfaces (CLIs) from absolutely any Python object.

Python Fire

Python Fire is a library for creating command line interfaces (CLIs) from absolutely any Python object.

  • Python Fire is a simple way to create a CLI in Python. [1]
  • Python Fire is a helpful tool for developing and debugging Python code. [2]
  • Python Fire helps with exploring existing code or turning other people's code into a CLI. [3]
  • Python Fire makes transitioning between Bash and Python easier. [4]
  • Python Fire makes using a Python REPL easier by setting up the REPL with the modules and variables you'll need already imported and created. [5]


pip install fire

Basic Usage

You can call Fire on any Python object:
functions, classes, modules, objects, dictionaries, lists, tuples, etc. They all work!

Here's a simple example.

import fire

class Calculator(object):
  """A simple calculator class."""

  def double(self, number):
    return 2 * number

if __name__ == '__main__':

Then, from the command line, you can run:

python double 10  # 20
python double --number=15  # 30

To learn how Fire behaves on functions, objects, dicts, lists, etc, and to learn about Fire's other features, see the Using a Fire CLI page.

For additional examples, see The Python Fire Guide.

Why is it called Fire?

When you call Fire, it fires off (executes) your command.

Where can I learn more?

Please see The Python Fire Guide.


installpip install fire
Creating a CLICommandNotes
importimport fire
Callfire.Fire()Turns the current module into a Fire CLI.
Callfire.Fire(component)Turns component into a Fire CLI.
Using a CLICommandNotes
Helpcommand -- --help
REPLcommand -- --interactiveEnters interactive mode.
Separatorcommand -- --separator=XThis sets the separator to X. The default separator is -.
Completioncommand -- --completionGenerate a completion script for the CLI.
Tracecommand -- --traceGets a Fire trace for the command.
Verbosecommand -- --verbose
Note that flags are separated from the Fire command by an isolated -- arg.


This is not an official Google product.