gird 2.1.0

Make-like build tool & task runner for Python

Gird

Gird is a lightweight & general-purpose Make-like build tool & task runner for Python.

Features

• A simple, expressive, and intuitive rule definition and execution scheme very close to that of Make.
• Configuration in Python, allowing straightforward and familiar usage, without the need for a dedicated rule definition syntax.
• Ability to take advantage of Python's flexibility and possibility to easily integrate with Python libraries and tools.
• Emphasis on API simplicity & ease of use.

Example use cases

• Data science & data analytics workflows.
• Portable CI tasks.
• Less rule-heavy application build setups. (Build time overhead may become noticeable with thousands of rules.)
• Any project with tasks that need to be executed automatically when some dependencies are updated.

Installation

Install Gird from PyPI with pip install gird, or from sources with pip install ..

Gird requires Python version 3.9 or newer, and is supported on Linux & macOS.

Usage

Define rules in girdfile.py. Depending on the composition of a rule definition, a rule can, for example,

• define a recipe to run a task, e.g., to update a target file,
• define prerequisites for the target, such as dependency files or other rules, and
• use Python functions for more complex dependency & recipe functionality.

A rule is invoked by gird {target}. To list rules, run gird list.

When invoked, a rule will be run if its target is considered outdated. This is the case if the rule

1. has a Phony target,
2. has a Path/TimeTracked target that does not exist,
3. has a Path/TimeTracked target and a Path/TimeTracked dependency that is more recent than the target,
4. has an outdated Rule/target as a dependency, or
5. has a function dependency that returns True.

Rules with outdated targets are run in topological order within the dependency graph, i.e., all outdated dependencies are updated before the respective targets.

Python functions used as recipes need to be picklable when used in rules defined with parallel=True (default). I.e., Lambda functions and locally defined functions require parallel=False.

Example rules

A rule with files as its target & dependency

import pathlib
import gird
WHEEL = pathlib.Path("package.whl")

RULE_BUILD = gird.rule(
    target=WHEEL,
    deps=pathlib.Path("module.py"),
    recipe="python -m build --wheel",
)

A rule with a phony target

RULE_TEST = gird.rule(
    target=gird.Phony("test"),
    deps=WHEEL,
    recipe="pytest",
)

A rule with other rules as dependencies

Group multiple rules together, and set the order of execution between rules.

gird.rule(
    target=gird.Phony("all"),
    deps=[
        RULE_TEST,
        RULE_BUILD,
    ],
)

A rule with a Python function recipe

To parameterize a function recipe for reusability, use, e.g., functools.partial.

import json
import functools
JSON1 = pathlib.Path("file1.json")
JSON2 = pathlib.Path("file2.json")

def create_target(json_in: pathlib.Path, json_out: pathlib.Path):
     json_out.write_text(
         json.dumps(
             json.loads(
                 json_in.read_text()
             ).update(value2="value2")
         )
     )

gird.rule(
    target=JSON2,
    deps=JSON1,
    recipe=functools.partial(create_target, JSON1, JSON2),
    parallel=True,
)

A Python function as a dependency to arbitrarily trigger rules

Below, have a remote file re-fetched if it has changed.

def has_remote_changed():
    return get_checksum_local() != get_checksum_remote()

gird.rule(
    target=JSON1,
    deps=has_remote_changed,
    recipe=fetch_remote,
)

Compound recipes for mixing shell commands with Python functions

gird.rule(
    target=JSON1,
    recipe=[
        "login",
        fetch_remote,
    ],
)

Implement the TimeTracked protocol for custom targets & dependencies

For example, define platform-specific logic to apply dependency tracking on a remote file.

class RemoteFile(gird.TimeTracked):
    def __init__(self, url: str):
        self._url = url
    @property
    def id(self):
        return self._url
    @property
    def timestamp(self):
        return get_remote_file_timestamp(self._url)

gird.rule(
    target=JSON1,
    deps=RemoteFile(URL),
    recipe=fetch_remote,
)

Flexible rule definition with loops and other constructs

RULES = [
    gird.rule(
        target=source.with_suffix(".json.gz"),
        deps=gird.rule(
            target=source,
            recipe=functools.partial(fetch_remote, source),
        ),
        recipe=f"gzip -k {source.resolve()}",
    )
    for source in [JSON1, JSON2]
]

Example girdfile.py

This is the girdfile.py of the project itself.

from itertools import chain
from pathlib import Path

from gird import Phony, rule
from scripts import assert_readme_updated, get_wheel_path, render_readme

WHEEL_PATH = get_wheel_path()

RULE_PYTEST = rule(
    target=Phony("pytest"),
    recipe="pytest -n auto --cov=gird --cov-report=xml",
    help="Run pytest & get code coverage report.",
)

RULE_MYPY = rule(
    target=Phony("mypy"),
    recipe="mypy --check-untyped-defs -p gird",
    help="Run mypy.",
)

RULE_CHECK_FORMATTING = rule(
    target=Phony("check_formatting"),
    recipe=[
        "black --check gird scripts test girdfile.py",
        "isort --check gird scripts test girdfile.py",
    ],
    help="Check formatting with Black & isort.",
)

RULE_CHECK_README_UPDATED = rule(
    target=Phony("check_readme_updated"),
    recipe=assert_readme_updated,
    help="Check that README.md is updated based on README_template.md.",
)

RULES_TEST = [
    RULE_PYTEST,
    RULE_MYPY,
    RULE_CHECK_FORMATTING,
    RULE_CHECK_README_UPDATED,
]

rule(
    target=Phony("test"),
    deps=RULES_TEST,
    help="\n".join(f"- {rule.help}" for rule in RULES_TEST),
)

rule(
    target=Path("README.md"),
    deps=chain(
        *(Path(path).iterdir() for path in ("scripts", "gird")),
        [Path("girdfile.py"), Path("pyproject.toml")],
    ),
    recipe=render_readme,
    help="Render README.md based on README_template.md.",
)

rule(
    target=WHEEL_PATH,
    recipe="poetry build --format wheel",
    help="Build distribution packages for the current version.",
)

rule(
    target=Phony("publish"),
    deps=WHEEL_PATH,
    recipe=f"twine upload --repository gird {WHEEL_PATH}",
    help="Publish packages of the current version to PyPI.",
)

Respective output from gird list:

pytest
    Run pytest & get code coverage report.
mypy
    Run mypy.
check_formatting
    Check formatting with Black & isort.
check_readme_updated
    Check that README.md is updated based on README_template.md.
test
    - Run pytest & get code coverage report.
    - Run mypy.
    - Check formatting with Black & isort.
    - Check that README.md is updated based on README_template.md.
README.md
    Render README.md based on README_template.md.
dist/gird-2.1.0-py3-none-any.whl
    Build distribution packages for the current version.
publish
    Publish packages of the current version to PyPI.