By default, click adds a --help option that outputs a standardised usage text based on the structure of the click commands:
Usage: ...
Options: ...
Commands:
...
...
How to override this behaviour to have a custom help output ? What I am trying to do is to output a custom message using rich library.
The trick is to create a click.Group class and override format_help method
class RichGroup(click.Group):
def format_help(self, ctx, formatter):
sio = io.StringIO()
console = rich.Console(file=sio, force_terminal=True)
console.print("Hello, [bold magenta]World[/bold magenta]!", ":vampire:")
formatter.write(sio.getvalue())
@click.group(cls=RichGroup)
def cli():
pass
To add to the already accepted answer, you can also subclass click.Command if you only need this custom functionality for a command:
class HelpfulCmd(click.Command):
def format_help(self, ctx, formatter):
click.echo("My custom help message")
@click.command(cls=HelpfulCmd)
def mycommand():
pass
formatter.write instead of click.echo
clickis that it make sense out of the box. I think if you want to extend click, you might want to write an extension. Have a look at github.com/click-contrib perhaps you can find another project that uses the API you need.