Write and manage your project's development scripts with modern Python syntax.
The project's name comes from the Japanese verb やる, which means "to do".
- 🗂️ Lightweight package with zero dependencies.
- 🐍 Supports modern Python versions (>=3.12).
- 🚀 Simply write your development scripts as Python functions.
- 🖥️ Supports macOS, Linux, and Windows.
If using the uv package manager:
uv add --dev yaruIf using pip:
pip install yaruYaru's documentation is available at https://github.com/c0dearm/yaru.
Simply decorate your Python functions to convert them into cli commands:
# :commands.py file
from typing import Annotated
from yaru import Arg, Context, command
# Add two numbers
@command
def add_numbers(c: Context, a: int, b: int) -> None:
"""Given `a` and `b`, print the sum of both numbers to stdout."""
print(a + b)The decorated functions must be discovered by yaru, so they need to be in a module named commands at
the root of your project, for example a commands.py file.
The add_numbers command is now invokable through the cli, this is the output of yaru --help:
usage: yaru [-h] {add-numbers} ...
Project's development commands
positional arguments:
{add-numbers}
add-numbers Add two numbers
options:
-h, --help show this help message and exit
For specific help on the command usage, you can do: yaru add-numbers --help:
usage: yaru add-numbers [-h] a b
Given `a` and `b`, print the sum of both numbers to stdout.
positional arguments:
a
b
options:
-h, --help show this help message and exit
Running the command yaru add-numbers 42 69 in your terminal will output 111.
The help text for the cli command is automatically parsed from the comments immiediatelly preceding the decorated function. Similarly, the command's description is obtained from the function's docstrings.
Moreover, you can use annotated type hints on your function's arguments in order to add help texts to the command's parameters too:
# :commands.py file
from typing import Annotated
from yaru import Arg, Context, command
# Add two numbers
@command
def add_numbers(
c: Context,
a: Annotated[int, Arg(help="First operand")],
b: Annotated[int, Arg(help="Second operand")],
) -> None:
"""Given `a` and `b`, print the sum of both numbers to stdout."""
print(a + b)The add-numbers cli help will now display as:
usage: yaru add-numbers [-h] a b
Given `a` and `b`, print the sum of both numbers to stdout.
positional arguments:
a First operand
b Second operand
options:
-h, --help show this help message and exit
If you define the function's arguments as optional (keyword arguments with defaults), yaru will treat
them as such in the cli. For example:
# :commands.py file
from yaru import Context, command
@command
def say_something(c: Context, phrase: str, twice: bool = False) -> None:
print(phrase)
if twice:
print(phrase)Will be handled like this:
usage: yaru say-something [-h] [--twice | --no-twice] phrase
positional arguments:
phrase
options:
-h, --help show this help message and exit
--twice, --no-twice
You may have noticed an extra first Context argument in all the commands. This is automatically injected
by yaru and provides a handy method run to execute instructions in your shell.
Going back to the example of number addition, we could do this in bash instead of python:
# :commands.py file
from yaru import Context, command
# Add two numbers
@command
def add_numbers(c: Context, a: int, b: int) -> None:
c.run(f"echo $(({a} + {b}))")The behavior when executed is exactly the same.
We welcome contributions! Please read our CONTRIBUTING.md file for guidelines on how to contribute to this project.
Yaru exists thanks to pyinvoke, which was the main inspirer.
Yaru is licensed under the MIT license (LICENSE or https://opensource.org/licenses/MIT)