rich-click

Format click help output nicely with Rich.

• Click is a "Python package for creating beautiful command line interfaces".
• Rich is a "Python library for rich text and beautiful formatting in the terminal".

The intention of rich-click is to provide attractive help output from click, formatted with rich, with minimal customisation required.

Features

• 🌈 Rich command-line formatting of click help and error messages
• 💫 Nice styles be default, usage is simply import rich_click as click
• 💻 CLI tool to run on other people's tools (prefix the command with rich-click)
• 🎁 Group commands and options into named panels
• ❌ Well formatted error messages
• 🔢 Easily give custom sort order for options and commands
• 🎨 Extensive customisation of styling and behaviour possible

Screenshot from examples/03_groups_sorting.py

Installation

You can install rich-click from the Python Package Index (PyPI) with pip or equivalent.

python -m pip install rich-click

Conda users can find rich-click on conda forge. Just set up conda to use conda-forge (see docs) then run:

conda install rich-click

Users on macOS can install rich-click via MacPorts.

sudo port install py-rich-click

Note that rich-click requires click>=7 but formatted subcommands (groups) only work with click>=8. With v7 the output simply reverts to default click output.

Usage

Import as click

To use rich-click, switch out your normal click import with rich-click, using the same namespace:

import rich_click as click

That's it ✨ Then continue to use click as you would normally.

See examples/01_simple.py for an example.

The intention is to maintain most / all of the normal click functionality and arguments. If you spot something that breaks or is missing once you start using the plugin, please create an issue about it.

Declarative

If you prefer, you can RichGroup or RichCommand with the cls argument in your click usage instead. This means that you can continue to use the unmodified click package in parallel.

See examples/02_declarative.py for an example.

Command-line usage

rich-click comes with a CLI tool that allows you to format the click help output from any package. As long as that tool is using click and isn't already passing custom cls objects, it should work. However, please consider it an experimental feature at this point.

To use, simply prefix to your normal command. For example, to get richified click help text from a package called awesometool, you could run:

$ rich-click awesometool --help

Usage: awesometool [OPTIONS]
..more richified output below..

Patching

In some situations, you might be registering a command from another Click CLI that does not use Rich-Click:

import rich_click as click
from some_library import another_cli

@click.group("my-cli")
def cli():
    pass

# `another_cli` will NOT have Rich-Click markup. :(
cli.add_command(another_cli)

In this situation, another_cli retains its original behavior. In order to make another_cli work with Rich-Click, you need to patch click before you import another_cli. You can patch Click with rich_click.cli.patch like this:

import rich_click as click
from rich_click.cli import patch

patch()

from some_library import another_cli  # noqa: E402

@click.group("my-cli")
def cli():
    pass

# `another_cli` will have Rich-Click markup. :)
cli.add_command(another_cli)

Customisation

There are a large number of customisation options in rich-click. These can be modified by changing variables in the click.rich_click namespace.

Note that most normal click options should still work, such as show_default=True, required=True and hidden=True.

Note: All images below are auto-generated using another side-project of mine: rich-codex. Pretty cool!

Using rich markup

In order to be as widely compatible as possible with a simple import, rich-click does not parse rich formatting markup (eg. [red]) by default. You need to opt-in to this behaviour.

To use rich markup in your help texts, add the following:

click.rich_click.USE_RICH_MARKUP = True

Remember that you'll need to escape any regular square brackets using a back slash in your help texts, for example: [dim]\[my-default: foo][\]

See examples/04_rich_markup.py for an example.

Using Markdown

If you prefer, you can use Markdown text. You must choose either Markdown or rich markup. If you specify both, Markdown takes preference.

click.rich_click.USE_MARKDOWN = True

See examples/05_markdown.py for an example.

Positional arguments

The default click behaviour is to only show positional arguments in the top usage string, and not in the list below with the options.

If you prefer, you can tell rich-click to show arguments with SHOW_ARGUMENTS. By default, they will get their own panel but you can tell rich-click to bundle them together with GROUP_ARGUMENTS_OPTIONS:

click.rich_click.SHOW_ARGUMENTS = True
click.rich_click.GROUP_ARGUMENTS_OPTIONS = True

See examples/06_arguments.py for an example.

Metavars and option choices

Metavars are click's way of showing expected input types. For example, if you have an option that must be an integer, the metavar is INTEGER. If you have a choice, the metavar is a list of the possible values.

By default, rich-click shows metavars in their own column. However, if you have a long list of choices, this column can be quite wide and result in a lot of white space:

It may look better to show metavars appended to the help text, instead of in their own column. For this, use the following:

click.rich_click.SHOW_METAVARS_COLUMN = False
click.rich_click.APPEND_METAVARS_HELP = True

See examples/08_metavars.py for an example.

Error messages

By default, rich-click gives some nice formatting to error messages:

You can customise the Try 'command --help' for help. message with ERRORS_SUGGESTION using rich-click though, and add some text after the error with ERRORS_EPILOGUE.

For example, from examples/07_custom_errors.py:

click.rich_click.STYLE_ERRORS_SUGGESTION = "magenta italic"
click.rich_click.ERRORS_SUGGESTION = "Try running the '--help' flag for more information."
click.rich_click.ERRORS_EPILOGUE = "To find out more, visit [link=https://mytool.com]https://mytool.com[/link]"

See examples/07_custom_errors.py for an example.

Help width

The default behaviour of rich-click is to use the full width of the terminal for output. However, if you've carefully crafted your help texts for the default narrow click output, you may find that you now have a lot of whitespace at the side of the panels.

To limit the maximum width of the help output, set MAX_WIDTH in characters, as follows:

click.rich_click.MAX_WIDTH = 100

Styling

Most aspects of rich-click formatting can be customised, from colours to alignment.

For example, to print the option flags in a different colour, you can use:

click.rich_click.STYLE_OPTION = "magenta"

To add a blank line between rows of options, you can use:

click.rich_click.STYLE_OPTIONS_TABLE_LEADING = 1
click.rich_click.STYLE_OPTIONS_TABLE_BOX = "SIMPLE"

You can make some really horrible colourful solutions using these styles if you wish:

See examples/10_table_styles.py for an example.

See the Configuration options section below for the full list of available options.

Groups and sorting

rich-click gives functionality to list options and subcommands in groups, printed as separate panels. It accepts a list of options / commands which means you can also choose a custom sorting order.

• For options (flags), set click.rich_click.OPTION_GROUPS
• For subcommands (groups), set click.rich_click.COMMAND_GROUPS

See examples/03_groups_sorting.py for a full example.

Options

To group option flags into two sections with custom names, see the following example:

click.rich_click.OPTION_GROUPS = {
    "mytool": [
        {
            "name": "Simple options",
            "options": ["--name", "--description", "--version", "--help"],
        },
        {
            "name": "Advanced options",
            "options": ["--force", "--yes", "--delete"],
        },
    ]
}

If you omit name it will use Commands (can be configured with OPTIONS_PANEL_TITLE).

Commands

Here we create two groups of commands for the base command of mytool. Any subcommands not listed will automatically be printed in a panel at the end labelled "Commands" as usual.

click.rich_click.COMMAND_GROUPS = {
    "mytool": [
        {
            "name": "Commands for uploading",
            "commands": ["sync", "upload"],
        },
        {
            "name": "Download data",
            "commands": ["get", "fetch", "download"],
        },
    ]
}

If you omit name it will use Commands (can be configured with COMMANDS_PANEL_TITLE).

Multiple commands

If you use multiple nested subcommands, you can specify their commands using the top-level dictionary keys:

click.rich_click.COMMAND_GROUPS = {
    "mytool": [{"commands": ["sync", "auth"]}],
    "mytool sync": [
        {
            "name": "Commands for uploading",
            "commands": ["sync", "upload"],
        },
        {
            "name": "Download data",
            "commands": ["get", "fetch", "download"],
        },
    ],
    "mytool auth":[{"commands": ["login", "logout"]}],
}

Table styling

Typically you would style the option / command tables using the global config options. However, if you wish you may style tables on a per-group basis using the table_styles key:

click.rich_click.COMMAND_GROUPS = {
    "mytool": [
        {
            "commands": ["sync", "auth"],
            "table_styles": {
                "show_lines": True,
                "row_styles": ["magenta", "yellow", "cyan", "green"],
                "border_style": "red",
                "box": "DOUBLE",
            },
        },
    ],
}

The available keys are: show_lines, leading, box, border_style, row_styles, pad_edge, padding.

Configuration options

Here is the full list of config options:

# Default styles
STYLE_OPTION = "bold cyan"
STYLE_ARGUMENT = "bold cyan"
STYLE_SWITCH = "bold green"
STYLE_METAVAR = "bold yellow"
STYLE_METAVAR_APPEND = "dim yellow"
STYLE_METAVAR_SEPARATOR = "dim"
STYLE_HEADER_TEXT = ""
STYLE_FOOTER_TEXT = ""
STYLE_USAGE = "yellow"
STYLE_USAGE_COMMAND = "bold"
STYLE_DEPRECATED = "red"
STYLE_HELPTEXT_FIRST_LINE = ""
STYLE_HELPTEXT = "dim"
STYLE_OPTION_HELP = ""
STYLE_OPTION_DEFAULT = "dim"
STYLE_OPTION_ENVVAR = "dim yellow"
STYLE_REQUIRED_SHORT = "red"
STYLE_REQUIRED_LONG = "dim red"
STYLE_OPTIONS_PANEL_BORDER = "dim"
ALIGN_OPTIONS_PANEL = "left"
STYLE_OPTIONS_TABLE_SHOW_LINES = False
STYLE_OPTIONS_TABLE_LEADING = 0
STYLE_OPTIONS_TABLE_PAD_EDGE = False
STYLE_OPTIONS_TABLE_PADDING = (0, 1)
STYLE_OPTIONS_TABLE_BOX = ""
STYLE_OPTIONS_TABLE_ROW_STYLES = None
STYLE_OPTIONS_TABLE_BORDER_STYLE = None
STYLE_COMMANDS_PANEL_BORDER = "dim"
ALIGN_COMMANDS_PANEL = "left"
STYLE_COMMANDS_TABLE_SHOW_LINES = False
STYLE_COMMANDS_TABLE_LEADING = 0
STYLE_COMMANDS_TABLE_PAD_EDGE = False
STYLE_COMMANDS_TABLE_PADDING = (0, 1)
STYLE_COMMANDS_TABLE_BOX = ""
STYLE_COMMANDS_TABLE_ROW_STYLES = None
STYLE_COMMANDS_TABLE_BORDER_STYLE = None
STYLE_ERRORS_PANEL_BORDER = "red"
ALIGN_ERRORS_PANEL = "left"
STYLE_ERRORS_SUGGESTION = "dim"
STYLE_ABORTED = "red"
MAX_WIDTH = None  # Set to an int to limit to that many characters
COLOR_SYSTEM = "auto"  # Set to None to disable colors

# Fixed strings
HEADER_TEXT = None
FOOTER_TEXT = None
DEPRECATED_STRING = "(Deprecated) "
DEFAULT_STRING = "[default: {}]"
ENVVAR_STRING = "[env var: {}]"
REQUIRED_SHORT_STRING = "*"
REQUIRED_LONG_STRING = "[required]"
RANGE_STRING = " [{}]"
APPEND_METAVARS_HELP_STRING = "({})"
ARGUMENTS_PANEL_TITLE = "Arguments"
OPTIONS_PANEL_TITLE = "Options"
COMMANDS_PANEL_TITLE = "Commands"
ERRORS_PANEL_TITLE = "Error"
ERRORS_SUGGESTION = None  # Default: Try 'cmd -h' for help. Set to False to disable.
ERRORS_EPILOGUE = None
ABORTED_TEXT = "Aborted."

# Behaviours
SHOW_ARGUMENTS = False  # Show positional arguments
SHOW_METAVARS_COLUMN = True  # Show a column with the option metavar (eg. INTEGER)
APPEND_METAVARS_HELP = False  # Append metavar (eg. [TEXT]) after the help text
GROUP_ARGUMENTS_OPTIONS = False  # Show arguments with options instead of in own panel
USE_MARKDOWN = False  # Parse help strings as markdown
USE_MARKDOWN_EMOJI = True  # Parse emoji codes in markdown :smile:
USE_RICH_MARKUP = False  # Parse help strings for rich markup (eg. [red]my text[/])
COMMAND_GROUPS = {}  # Define sorted groups of panels to display subcommands
OPTION_GROUPS = {}  # Define sorted groups of panels to display options and arguments
USE_CLICK_SHORT_HELP = False  # Use click's default function to truncate help text

Contributing

Contributions and suggestions for new features are welcome, as are bug reports! Please create a new issue or better still, dive right in with a pull-request.

Local setup

1. Create a new venv with a python3.7+ interpreter using python3 -m venv venv
2. Activate the venv with source venv/bin/activate
3. Install our the package as an editable including all dev dependencies with pip3 install -e ."[dev]"
4. Install pre-commit with pre-commit install

Pre-commit

Our pre-commit hooks contain the following hooks:

• Prettier: formats our markdown and yaml files nicely.
• no relative imports: prevents you from using relative imports.
• iSort: will automatically sort the imports alphabetically.
• black: will automatically format your code to be according to standardized python format.
• flake8: will do linting checks to make sure all your code is correctly styled and used.
• mypy: static type checker which verifies you are not using objects incorrectly.

As mentioned, some of these tools automatically fix your code while other only highlight potential issues. Sometimes it will be enough to try to commit a second time and it will pass, while other times it may require manual changes to your code.

In rare cases it may be difficult or undesirable to change to code to pass the linting rules. If this happens, it's ok to add a flake8 # noqa or mypy # type: ignore comment to skip that line. For details of how to do this, please see the flake8 docs and mypy docs.

Credits

This package was written by Phil Ewels (@ewels), based on initial code by Will McGugan (@willmcgugan). Furthermore, these contributors helped make the package what it is today:

• @harens
• @fridex
• @pawamoy
• @jorrick