typed-argparse 0.2.6

Write type-safe and elegant CLIs with a clear separation of concerns.

typed_argparse

💡 write type-safe and elegant CLIs with a clear separation of concerns.

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Motivation

Want to add type annotations to a code base that makes use of argparse without refactoring all you CLIs? typed_argparse allows to do that with minimal changes:

1. Add a type Args(TypedArgs) that inherits from TypedArgs and fill it with type annotations.
2. Wrap the result of e.g. your parse_args function with Args.
3. That's it, enjoy IDE auto-completion and strong type safety 😀.

Features

• Argument parsing based on type annotation (including runtime validation, and support for many common types)
• Clear separation of concern between argument parsing and business logic.
• Support for super-low-latency shell auto-completions.
• Great for writing sub-command CLIs.
• Very lightweight.
• No dependencies.
• Fully typed, no extra type stubs required.
• Offers both a high-level and a low-level API. The high-level API generally requires less code to write, is fully based on type annotations, and is the preferred way for writing new CLIs. The low-level API is mainly a low-effort migration path for incorporating type-safety into existing CLIs based on argparse.

Install

$ pip install typed-argparse

The only requirement is a modern Python (3.6+).

Basic Usage

import typed_argparse as tap


# 1. Argument definition
class Args(tap.TypedArgs):
    my_arg: str = tap.arg(help="some help")
    number_a: int = tap.arg(default=42, help="some help")
    number_b: Optional[int] = tap.arg(help="some help")
    verbose: bool = tap.arg(help="some help")
    names: List[str] = tap.arg(help="some help")


# 2. Business logic
def runner(args: Args):
    print(f"Running my app with args:\n{args}")


# 3. Bind & run argument definition + business logic
def main() -> None:
    tap.Parser(Args).bind(runner).run()

Documentation

See full documentation.

Changes

See change log.

License

This project is licensed under the terms of the MIT license.