python-fire

Introduction to Python Fire

Python Fire is a versatile library designed to simplify the creation of command line interfaces (CLIs) from any Python object. Developed with the aim of streamlining command line tasks, Python Fire is an indispensable tool for Python developers who need quick and efficient CLI solutions.

Key Benefits

• Simple CLI Generation: With Python Fire, creating a command line interface is as easy as calling a function. This simplicity reduces development time and effort.
• Development and Debugging Aid: This tool can be invaluable during the development phase, allowing developers to interact with and debug Python code more effectively.
• Code Exploration: Python Fire is perfect for converting existing codebases into a more accessible CLI format, aiding in exploring and understanding code.
• Smooth Transition from Bash: For those accustomed to Bash scripting, Python Fire eases the transition to Python by simplifying common command line operations.
• Enhanced Python REPL Experience: By preloading necessary modules and variables, Python Fire optimizes the interactive Python shell, making it ready to use from the start.

Installation

Python Fire can be easily installed using pip or conda. For a pip installation, simply run:

pip install fire

If you prefer conda, use:

conda install fire -c conda-forge

Alternatively, for those who like to work from the source, clone the repository and execute:

python setup.py install

Basic Usage

Python Fire can be invoked on any Python object, including functions, classes, modules, and even simple data structures like lists and dictionaries. This versatility makes it incredibly powerful for varied use cases.

Using Fire with a Function

Consider a simple example with a function:

import fire

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

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

From the command line, the function can be executed like so:

python hello.py  # Outputs: Hello World!
python hello.py --name=David  # Outputs: Hello David!
python hello.py --help  # Displays usage information.

Using Fire with a Class

Here's how you can integrate Fire with a basic class:

import fire

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

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

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

Command line usage for this class is straightforward:

python calculator.py double 10  # Outputs: 20
python calculator.py double --number=15  # Outputs: 30

Learn More

Python Fire is aptly named for its ability to quickly "fire off" commands once invoked. For those interested in a deep dive, more information is available in the Python Fire Guide.

Reference Commands

To integrate Python Fire into your projects, here are some quick reference commands:

• Setup: pip install fire
• Creating a CLI: Use import fire and invoke with fire.Fire() or fire.Fire(component) to turn your module or component into a CLI.
• Using Command Line Flags: Various flags like help, interactive, separator, completion, trace, and verbose can enhance functionality. These command-line options are separated by an -- from the main Fire command.

Python Fire is licensed under the Apache 2.0 License and is a testament to the flexible and streamlined CLI capabilities it brings to Python development. Although it originates from Google, it is not an official product of the company.