werr 0.1.0

A python project task runner

werr

A simple, opinionated, python project task runner.

A task is a configured sequence of commands to run.

[project]
name = "appletree"
version = "0.1.0"
dependencies = [
    "pysunlight==24.1",
]

[tool.werr]
# 'check' is the default task if `werr` is run with no arguments.
task.check = [
    "black --check {project}",
    "isort --check {project}",
    "ruff check {project}",
    "mypy {project}",
    "pytest",
]
task.fix = [
    "black {project}",
    "isort {project}",
    "ruff fix {project}",
]

Running werr executes each check command in sequence, printing which failed and how. The tool returns a non-zero exit code if any command fails.

Running werr fix executes each fix command in sequence.

NOTE: All commands are run using uv (the only dependency of this project).

Command Variables

The following {...} variables are provided by werr to be used in task commands:

• {project} - the absolute path to the directory containing the pyproject.toml file

Structured Output

werr         # interactive human readable output (default)
werr --json  # emit lines of JSON representing the result of each command
werr --xml   # print Junit XML for CI

Custom Tasks

Define a custom task with task.<name> = [ ... ]

[tool.werr]
# ...
task.docs = [
    "sphinx-build -b html {project}",
]

Running werr docs will build the documentation.

New Project

A suggested workflow for creating a new project is:

1. uv init
2. uv add --dev black ruff ty pytest
3. add tasks to [tool.werr]
4. uvx werr or add to dev group and in venv just werr