📄 python-fire/README

File: README.md | Updated: 11/18/2025

Python Fire PyPI

Python Fire is a library for automatically generating 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]

Installation

To install Python Fire with pip, run: pip install fire

To install Python Fire with conda, run: conda install fire -c conda-forge

To install Python Fire from source, first clone the repository and then run: python setup.py install

Basic Usage

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

Here's an example of calling Fire on a function.

import fire

def hello(name="World"):
  return "Hello %s!" % name

if __name__ == '__main__':
  fire.Fire(hello)

Then, from the command line, you can run:

python hello.py  # Hello World!
python hello.py --name=David  # Hello David!
python hello.py --help  # Shows usage information.

Here's an example of calling Fire on a class.

import fire

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

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

if __name__ == '__main__':
  fire.Fire(Calculator)

Then, from the command line, you can run:

python calculator.py double 10  # 20
python calculator.py 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.

Reference

| Setup | Command | Notes | :------ | :------------------ | :--------- | install | pip install fire |

| Creating a CLI | Command | Notes | :--------------| :--------------------- | :--------- | import | import fire | | Call | fire.Fire() | Turns the current module into a Fire CLI. | Call | fire.Fire(component) | Turns component into a Fire CLI.

| Using a CLI | Command | Notes | :---------------------------------------------- | :-------------------------------------- | :---- | Help | command --help or command -- --help | | REPL | command -- --interactive | Enters interactive mode. | Separator | command -- --separator=X | Sets the separator to X. The default separator is -. | Completion | command -- --completion [shell] | Generates a completion script for the CLI. | Trace | command -- --trace | Gets a Fire trace for the command. | Verbose | command -- --verbose |

Note that these flags are separated from the Fire command by an isolated --.

License

Licensed under the Apache 2.0 License.

Disclaimer

This is not an official Google product.