tyro

     

tyro.cli() is a tool for generating CLI interfaces in Python.

We can define configurable scripts using functions:

"""A command-line interface defined using a function signature.

Usage: python script_name.py --foo INT [--bar STR]
"""

import tyro

def main(
    foo: int,
    bar: str = "default",
) -> None:
    ...  # Main body of a script.

if __name__ == "__main__":
    # Generate a CLI and call `main` with its two arguments: `foo` and `bar`.
    tyro.cli(main)

Or instantiate config objects defined using tools like dataclasses, pydantic, and attrs:

"""A command-line interface defined using a class signature.

Usage: python script_name.py --foo INT [--bar STR]
"""

from dataclasses import dataclass
import tyro

@dataclass
class Config:
    foo: int
    bar: str = "default"

if __name__ == "__main__":
    # Generate a CLI and instantiate `Config` with its two arguments: `foo` and `bar`.
    config = tyro.cli(Config)

    # Rest of script.
    assert isinstance(config, Config)  # Should pass.

Other features include helptext generation, nested structures, subcommands, and shell completion.

Why tyro?

1. Define things once. Standard Python type annotations, docstrings, and default values are parsed to automatically generate command-line interfaces with informative helptext.

2. Static types. Unlike tools dependent on dictionaries, YAML, or dynamic namespaces, arguments populated by tyro benefit from IDE and language server-supported operations — tab completion, rename, jump-to-def, docstrings on hover — as well as static checking tools like pyright and mypy.

3. Modularity. tyro supports hierarchical configuration structures, which make it easy to decentralize definitions, defaults, and documentation.