How to have a single option that allows multiple values without repeating the option

[Timmmm]

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 tutorials in the docs and didn't find an answer.
• I already checked if it is not related to Typer but to Click.

Commit to Help

• I commit to help with one of those options 👆

Example Code

from typing import List, Optional

import typer
from typing_extensions import Annotated


def main(user: Annotated[Optional[List[str]], typer.Option()] = None):
    if not user:
        print(f"No provided users (raw input = {user})")
        raise typer.Abort()
    for u in user:
        print(f"Processing user: {u}")


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

Description

The code above requires you do use --user a --user b. Is there a way to make it accept --user a b instead?

Operating System

Linux

Operating System Details

No response

Typer Version

0.16.0

Python Version

3.12

Additional Context

No response

[kinuax]

Typer only supports a fixed number of values for list CLI option. Source: https://typer.tiangolo.com/tutorial/multiple-values/options-with-multiple-values/

If you want to keep --user only once, you may pass a random number of users separating them with anything but a space.

from typing_extensions import Annotated

import typer

separator = ","  # May be "|", "#", "-", etc.
assert separator not in ["", " "]


def str_to_list(value: str) -> list[str]:
    return value.split(separator)


def main(user: Annotated[list | None, typer.Option(parser=str_to_list)] = None):
    if not user:
        print(f"No provided users (raw input = {user})")
        raise typer.Abort()
    for u in user:
        print(f"Processing user: {u}")


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

Note that replacing list with list[str] in the Annotated type generates a list of lists.

[Timmmm]

Ah cool that's what I ended up doing, thanks! Probably better anyway because it's less ambiguous.