Configuration via typing.Annotated[]

The tyro.conf module contains utilities that can be used to configure command-line interfaces beyond what is expressible via static type annotations.

Features here are supported, but generally unnecessary and should be used sparingly.

import dataclasses

from typing_extensions import Annotated

import tyro


@dataclasses.dataclass
class Args:
    # A numeric field parsed as a positional argument.
    positional: tyro.conf.Positional[int]

    # A boolean field with flag conversion turned off.
    boolean: tyro.conf.FlagConversionOff[bool] = False

    # A numeric field that can't be changed via the CLI.
    fixed: tyro.conf.Fixed[int] = 5

    # A field with manually overridden properties.
    manual: Annotated[
        str,
        tyro.conf.arg(
            name="renamed",
            metavar="STRING",
            help="A field with manually overridden properties!",
        ),
    ] = "Hello"


if __name__ == "__main__":
    print(tyro.cli(Args))

---

python 04_additional/07_conf.py --help

usage: 07_conf.py [-h] [OPTIONS] INT

╭─ positional arguments ─────────────────────────────────────────────────────╮
│ INT                     A numeric field parsed as a positional argument.   │
│                         (required)                                         │
╰────────────────────────────────────────────────────────────────────────────╯
╭─ options ──────────────────────────────────────────────────────────────────╮
│ -h, --help              show this help message and exit                    │
│ --boolean {True,False}  A boolean field with flag conversion turned off.   │
│                         (default: False)                                   │
│ --fixed {fixed}         A numeric field that can't be changed via the CLI. │
│                         (fixed to: 5)                                      │
│ --renamed STRING        A field with manually overridden properties!       │
│                         (default: Hello)                                   │
╰────────────────────────────────────────────────────────────────────────────╯

---

python 04_additional/07_conf.py 5 --boolean True

Args(positional=5, boolean=True, fixed=5, manual='Hello')