[Feature] positional-only args are always Arguments, keyword-only args are always Options, normal args are unchanged

[matthewgdv]

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Example Code

from pathlib import Path
import typer


# in this example we want 'workdir' to be Argument and we want 'name' and 'age' to be Option
def main(workdir: Path = Argument(Path.cwd()), name: str = typer.Option(...), age: int = typer.Option(...))
    ...


if __name__ == '__main__':
    typer.run(main)

Description

• Make it easier to write arguments with default values (uncommonly needed) and options without default values (often needed)
• Currently the most common cases where none of the extra arguments of typer.Argument or typer.Option are needed aside from the default value are more verbose than they need to be and don't take advantage of python's syntactic sugar for positional-only and keyword-only arguments

Wanted Solution

Have typer leave normal arguments the same as they are currently for backwards-compatibility but allow positional-only arguments to always create an Argument instance (even if given a default value), while keyword-only arguments would always result in an Option instance (even without a default value)

Wanted Code

from pathlib import Path
import typer


# 'workdir' will be interpreted as an Argument; 'name' and 'int' will each be interpreted as an Option
def main(workdir: Path = Path.cwd(), /, *, name: str, age: int)
    ...


if __name__ == '__main__':
    typer.run(main)

Alternatives

No response

Operating System

Windows

Operating System Details

No response

Typer Version

0.3.2

Python Version

Python 3.9.0rc1

Additional Context

No response