Positional Arguments

Positional-only arguments in functions are converted to positional CLI arguments.

For more general positional arguments, see tyro.conf.Positional.

from __future__ import annotations

import dataclasses
import enum
import pathlib
from typing import Tuple

import tyro


def main(
    source: pathlib.Path,
    dest: pathlib.Path,
    /,  # Mark the end of positional arguments.
    optimizer: OptimizerConfig,
    force: bool = False,
    verbose: bool = False,
    background_rgb: Tuple[float, float, float] = (1.0, 0.0, 0.0),
) -> None:
    """Command-line interface defined using a function signature. Note that this
    docstring is parsed to generate helptext.

    Args:
        source: Source path.
        dest: Destination path.
        optimizer: Configuration for our optimizer object.
        force: Do not prompt before overwriting.
        verbose: Explain what is being done.
        background_rgb: Background color. Red by default.
    """
    print(f"{source=}\n{dest=}\n{optimizer=}\n{force=}\n{verbose=}\n{background_rgb=}")


class OptimizerType(enum.Enum):
    ADAM = enum.auto()
    SGD = enum.auto()


@dataclasses.dataclass(frozen=True)
class OptimizerConfig:
    algorithm: OptimizerType = OptimizerType.ADAM
    """Gradient-based optimizer to use."""

    learning_rate: float = 3e-4
    """Learning rate to use."""

    weight_decay: float = 1e-2
    """Coefficient for L2 regularization."""


if __name__ == "__main__":
    tyro.cli(main)

---

python 04_additional/01_positional_args.py --help

usage: 01_positional_args.py [-h] [OPTIONS] PATH PATH

Command-line interface defined using a function signature. Note that this 
docstring is parsed to generate helptext.

╭─ positional arguments ─────────────────────────────────────────────────────╮
│ PATH                    Source path. (required)                            │
│ PATH                    Destination path. (required)                       │
╰────────────────────────────────────────────────────────────────────────────╯
╭─ options ──────────────────────────────────────────────────────────────────╮
│ -h, --help              show this help message and exit                    │
│ --force, --no-force     Do not prompt before overwriting. (default: False) │
│ --verbose, --no-verbose                                                    │
│                         Explain what is being done. (default: False)       │
│ --background-rgb FLOAT FLOAT FLOAT                                         │
│                         Background color. Red by default. (default: 1.0    │
│                         0.0 0.0)                                           │
╰────────────────────────────────────────────────────────────────────────────╯
╭─ optimizer options ────────────────────────────────────────────────────────╮
│ Configuration for our optimizer object.                                    │
│ ────────────────────────────────────────────────────────────────────────── │
│ --optimizer.algorithm {ADAM,SGD}                                           │
│                         Gradient-based optimizer to use. (default: ADAM)   │
│ --optimizer.learning-rate FLOAT                                            │
│                         Learning rate to use. (default: 0.0003)            │
│ --optimizer.weight-decay FLOAT                                             │
│                         Coefficient for L2 regularization. (default: 0.01) │
╰────────────────────────────────────────────────────────────────────────────╯

---

python 04_additional/01_positional_args.py ./a ./b --optimizer.learning-rate 1e-5

source=PosixPath('a')
dest=PosixPath('b')
optimizer=OptimizerConfig(algorithm=<OptimizerType.ADAM: 1>, learning_rate=1e-05, weight_decay=0.01)
force=False
verbose=False
background_rgb=(1.0, 0.0, 0.0)