Welcome to the Click Documentation¶
Click is a Python package for creating beautiful command line interfaces in a composable way with as little code as necessary. It’s the “Command Line Interface Creation Kit”. It’s highly configurable but comes with sensible defaults out of the box.
It aims to make the process of writing command line tools quick and fun while also preventing any frustration caused by the inability to implement an intended CLI API.
Click in three points:
- arbitrary nesting of commands
- automatic help page generation
- supports lazy loading of subcommands at runtime
What does it look like? Here is an example of a simple Click program:
import click @click.command() @click.option('--count', default=1, help='Number of greetings.') @click.option('--name', prompt='Your name', help='The person to greet.') def hello(count, name): """Simple program that greets NAME for a total of COUNT times.""" for x in range(count): click.echo('Hello %s!' % name) if __name__ == '__main__': hello()
And what it looks like when run:
$ python hello.py --count=3 Your name: John Hello John! Hello John! Hello John!
It automatically generates nicely formatted help pages:
$ python hello.py --help Usage: hello.py [OPTIONS] Simple program that greets NAME for a total of COUNT times. Options: --count INTEGER Number of greetings. --name TEXT The person to greet. --help Show this message and exit.
You can get the library directly from PyPI:
pip install click
This part of the documentation guides you through all of the library’s usage patterns.
- Why Click?
- Setuptools Integration
- Basic Value Options
- Multi Value Options
- Multiple Options
- Boolean Flags
- Feature Switches
- Choice Options
- Password Prompts
- Callbacks and Eager Options
- Yes Parameters
- Values from Environment Variables
- Multiple Values from Environment Values
- Other Prefix Characters
- Range Options
- Callbacks for Validation
- Commands and Groups
- User Input Prompts
- Documenting Scripts
- Complex Applications
- Advanced Patterns
- Testing Click Applications
- Bash Complete
- Exception Handling
- Python 3 Support
If you are looking for information on a specific function, class, or method, this part of the documentation is for you.