Composable Click callback utilities for building flexible CLI applications.
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Author: Adam Dangoor
Requires Python: >=3.11
Classifiers
Development Status
- 4 - Beta
Intended Audience
- Developers
Operating System
- OS Independent
Programming Language
- Python :: 3 :: Only
- Python :: 3.11
- Python :: 3.12
- Python :: 3.13
- Python :: 3.14
Topic
- Software Development :: Libraries :: Python Modules
Composable Click callback utilities for building flexible CLI applications.
Installation
$ pip install click-compose
Or with uv:
$ uv add click-compose
Quick Start
click-compose provides utilities for composing Click callbacks:
multi_callback
Combine multiple callbacks into a single callback that applies them in sequence. Use a tuple for type-checked, type-changing chains of up to ten callbacks:
"""Example of using multi_callback to combine validators."""
import click
from click_compose import multi_callback
def validate_positive(
_ctx: click.Context | None,
_param: click.Parameter | None,
value: int,
) -> int:
"""Validate that value is positive."""
if value <= 0:
msg = "Must be positive"
raise click.BadParameter(message=msg)
return value
MAX_VALUE = 100
def validate_max_100(
_ctx: click.Context | None,
_param: click.Parameter | None,
value: int,
) -> int:
"""Validate that value is at most 100."""
if value > MAX_VALUE:
msg = "Must be <= 100"
raise click.BadParameter(message=msg)
return value
@click.command()
@click.option(
"--count",
type=int,
callback=multi_callback(
callbacks=(validate_positive, validate_max_100),
),
)
def cmd(count: int) -> None:
"""Example command with multiple validators."""
click.echo(message=f"Count: {count}")
sequence_validator
Apply a validator to each element in a sequence (useful with multiple=True):
"""Example of using sequence_validator with multiple values."""
import click
from click_compose import sequence_validator
def validate_positive(
_ctx: click.Context | None,
_param: click.Parameter | None,
value: int,
) -> int:
"""Validate that value is positive."""
if value <= 0:
msg = "Must be positive"
raise click.BadParameter(message=msg)
return value
@click.command()
@click.option(
"--numbers",
multiple=True,
type=int,
callback=sequence_validator(validator=validate_positive),
)
def cmd(numbers: tuple[int, ...]) -> None:
"""Example command with sequence validation."""
click.echo(message=f"Sum: {sum(numbers)}")
deduplicate
Remove duplicates from a sequence while preserving order (useful with multiple=True):
"""Example of using ``deduplicate`` to remove duplicate values."""
import click
from click_compose import deduplicate
@click.command()
@click.option(
"--tags",
multiple=True,
type=str,
callback=deduplicate,
)
def cmd(tags: tuple[str, ...]) -> None:
"""Example command that removes duplicate tags."""
click.echo(message=f"Unique tags: {', '.join(tags)}")
Documentation
See the full documentation.
2026.9.16.1
Sep 16, 2026
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2026.9.8
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