Support secondary flags for non-boolean flags

[skeggse]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the Typer documentation, with the integrated search.
• I already searched in Google "How to X in Typer" and didn't find any information.
• I already read and followed all the tutorial in the docs and didn't find an answer.

Example Code

from typing import Annotated, Optional

from typer import Option, run


def main(glob: Annotated[Optional[str], Option("--glob/--no-glob")] = "*"):
    pass  # Do something with glob here, but handle the case that it's None.


if __name__ == "__main__":
    run(main)

Description

I'd like to be able to have --flag with a --no-flag counterpart. These would be mutually exclusive (not supported per #140), and the former would accept a string (as opposed to a boolean option, which currently provides this kind of flag pair.

Operating System

Linux, Windows, macOS

Operating System Details

No response

Typer Version

0.9.0

Python Version

3.9.16

Additional Context

No response

[pmav99]

The example code doesn't run. You need to apply the following diff:

-     run(main())
+     run(main)

[pmav99]

Wouldn't it be simpler to just a have an optional typer.Option named glob? For example:

from typing import Annotated, Optional

from typer import Option, run


def main(glob: Annotated[str, Option(help="help for glob")] = ""):
    print(locals())


if __name__ == "__main__":
    run(main)

Examples:

$ python aaa.py
{'glob': ''}
$ python aaa.py --glob "*"
{'glob': '*'}
$ python aaa.py --glob "*.txt"
{'glob': '*.txt'}

[skeggse]

I'd like the default to be *, and I'd like a way to disable the glob, and the actual flag is used in such a way that passing an empty string for the parameter is entirely non-obvious, which makes having a way to explicitly disable the functionality offered important to avoid people asking how to do that.

[pmav99]

AFAIK there is no out of the box way to express this in typer. Using click you can kind of do it with https://click.palletsprojects.com/en/8.1.x/options/#feature-switches

import click

@click.command()
@click.option('--glob', 'glob', flag_value='*', default=True)
@click.option('--no-glob', 'glob', flag_value='')
def info(glob) -> int:
    click.echo(locals())

info()

Example:

$ python aaa.py
{'glob': '*'}
$ python aaa.py --no-glob
{'glob': ''}

but you can't update the glob pattern.

[skeggse]

Yes, this is a feature request!

[YuriiMotov]

Not exactly what you want, but may be a workaround in some cases:

from typing import Annotated, Optional

from typer import Option, run


def main(
    glob: Annotated[Optional[str], Option()] = "*",
    no_glob: Annotated[bool, Option("--no-glob")] = False,
):
    glob = None if no_glob is True else glob
    print(glob)


if __name__ == "__main__":
    run(main)

Try it:

$ typer myapp.py run --no-glob
None

$ typer myapp.py run
*

$ typer myapp.py run --glob something --no-glob
None

$ typer myapp.py run --help
                                                                                                                                                         
 Usage: typer [PATH_OR_MODULE] run [OPTIONS]                                                                                                             
                                                                                                                                                         
 Run the provided Typer app.                                                                                                                             
                                                                                                                                                         
╭─ Options ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ --glob           TEXT  [default: *]                                                                                                                   │
│ --no-glob                                                                                                                                             │
│ --help                 Show this message and exit.                                                                                                    │
╰───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯