Optional Tuples break typer

[multimeric]

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Example Code

from typing import Optional, Tuple
import typer

def main(arg: Optional[Tuple[int]] = None):
    pass

typer.run(main)

╭─────────────────────────────── Traceback (most recent call last) ────────────────────────────────╮
│ /opt/anaconda3/envs/napari-env/lib/python3.9/site-packages/typer/main.py:650 in                  │
│ internal_convertor                                                                               │
╰──────────────────────────────────────────────────────────────────────────────────────────────────╯
TypeError: 'NoneType' object is not iterable

Description

Typer seems to hit this error when it encounters Optional[Tuple[...]]. It's readily reproducible.

Operating System

macOS

Operating System Details

Monterey, 12.6

Typer Version

0.9.0

Python Version

3.9.16

Additional Context

No response

[Asthestarsfalll]

Same problem

[svlandeg]

Hi!

To configure an option that expects multiple values, you can use a List:

def main(arg: Optional[List[int]] = None):
    pass

or with Annotated:

def main(arg: Annotated[Optional[List[int]], typer.Option()] = None):
    pass

[multimeric]

A list accepts an arbitrary number of values, whereas a type such as Optional[Tuple[int, int]] means "allow either None, or two integers, but not one integer or three etc". So your solution doesn't solve my use case.

[svlandeg]

That's true, and it does look like that's not quite supported yet, and we'll look into it.

[Asthestarsfalll]

I submit a PR to support this