4-line Usage: when using Literal type

[pjonsson]

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

import typer
from typing import Literal, get_args

# Does not work:
# type ALL_PRODUCT_TYPES_T = Literal[
ALL_PRODUCT_TYPES_T = Literal[
    "Longlonglongname1:more_long_things_here",
    "Longname2:NUM1ABC",
    "Longname2:NUM1ABC_delete",
    "Longname2:NUM2ABC",
    "Longname2:NUM2ABC_delete",
    "Longname3:NU_3_ABC___",
    "Longname3:NU_2_CDE___",
    "Longname3:NU_2_CDE____delete",
]

ALL_PRODUCT_TYPES: tuple[ALL_PRODUCT_TYPES_T, ...] = get_args(ALL_PRODUCT_TYPES_T)

app = typer.Typer()


@app.command()
def main(
    product_type: ALL_PRODUCT_TYPES_T = typer.Argument(...),
    # Type should really be list[ALL_PRODUCT_TYPES_T].
    more_products: list[str] = typer.Argument(..., help=" ".join(ALL_PRODUCT_TYPES))
) -> None:
    pass


if __name__ == "__main__":
    app()

Description

I find the help text from the new Literal support quite hard to read, here's the output from the attached reproducer:

$ uv run ./test.py --help

 Usage: test.py [OPTIONS] PRODUCT_TYPE:{Longlonglongname1:more_long_things|Long
                name2:NUM1ABC|Longname2:NUM1ABC_delete|Longname2:NUM2ABC|Longna
                me2:NUM2ABC_delete|Longname3:NU_3_ABC___|Longname3:NU_2_CDE___|
                Longname3:NU_2_CDE____delete} MORE_PRODUCTS...

╭─ Arguments ──────────────────────────────────────────────────────────────────╮
│ *    product_type       PRODUCT_TYPE:{Longlonglo  [required]                 │
│                         ngname1:more_long_things                             │
│                         |Longname2:NUM1ABC|Longn                             │
│                         ame2:NUM1ABC_delete|Long                             │
│                         name2:NUM2ABC|Longname2:                             │
│                         NUM2ABC_delete|Longname3                             │
│                         :NU_3_ABC___|Longname3:N                             │
│                         U_2_CDE___|Longname3:NU_                             │
│                         2_CDE____delete}                                     │
│ *    more_products      MORE_PRODUCTS...          Longlonglongname1:more_lo… │
│                                                   Longname2:NUM1ABC,         │
│                                                   Longname2:NUM1ABC_delete,  │
│                                                   Longname2:NUM2ABC,         │
│                                                   Longname2:NUM2ABC_delete,  │
│                                                   Longname3:NU_3_ABC___,     │
│                                                   Longname3:NU_2_CDE___,     │
│                                                   Longname3:NU_2_CDE____del… │

I think the 4 line Usage: is worse than the non-literal version that I've been using so far (passing help=str(['Longlonglongname1:more_long_things', ...]) to typer.Argument):

 Usage: cli.py [OPTIONS] PRODUCT_TYPE NAME

╭─ Arguments ──────────────────────────────────────────────────────────────────╮
│ *    product_type      TEXT  ('Longlonglongname1:more_long_things',          │
│                              'Longname2:NUM1ABC',                            │
│                              'Longname2:NUM1ABC_delete',                     │
│                              'Longname2:NUM2ABC',                            │
│                              'Longname2:NUM2ABC_delete',                     │
│                              'Longname3:NU_3_ABC___',                        │
│                              'Longname3:NU_2_CDE___',                        │
│                              'Longname3:NU_2_CDE____delete')                 │
│                              [required]                                      │

Is there some toggle to avoid making a multi-line Usage-line or similar?

I also get a failure in Typer if I use type ALL_PRODUCT_TYPES_T = Literal[... when defining the type for some reason (using the 3.12 syntax for type aliases requires changing the RHS of ALL_PRODUCT_TYPES to get_args(ALL_PRODUCT_TYPES_T.__value__), but that is unrelated to Typer), is that intentional?

Operating System

Linux

Operating System Details

No response

Typer Version

0.19.2

Python Version

3.12

Additional Context

No response

[YuriiMotov]

You can configure Usage using metavar parameter:

import typer
from typing import Literal, get_args

ALL_PRODUCT_TYPES_T = Literal[
    "Longlonglongname1:more_long_things_here",
    "Longname2:NUM1ABC",
    "Longname2:NUM1ABC_delete",
    "Longname2:NUM2ABC",
    "Longname2:NUM2ABC_delete",
    "Longname3:NU_3_ABC___",
    "Longname3:NU_2_CDE___",
    "Longname3:NU_2_CDE____delete",
]

app = typer.Typer()


def get_help_for_literal(literal_type: type) -> str:
    values = get_args(literal_type)
    return "\n\n".join(f"'{value}'" for value in values)


@app.command()
def main(
    product_type: ALL_PRODUCT_TYPES_T = typer.Argument(
        ..., metavar="PRODUCT_TYPE", help=get_help_for_literal(ALL_PRODUCT_TYPES_T)
    ),
) -> None:
    pass


if __name__ == "__main__":
    app()

Result:

$ typer main.py run --help
                                                                                                 
 Usage: typer [PATH_OR_MODULE] run [OPTIONS] PRODUCT_TYPE                                        
                                                                                                 
 Run the provided Typer app.                                                                     
                                                                                                 
╭─ Arguments ───────────────────────────────────────────────────────────────────────────────────╮
│ *    product_type      CHOICE  'Longlonglongname1:more_long_things_here' [required]           │
│                                'Longname2:NUM1ABC'                                            │
│                                'Longname2:NUM1ABC_delete'                                     │
│                                'Longname2:NUM2ABC'                                            │
│                                'Longname2:NUM2ABC_delete'                                     │
│                                'Longname3:NU_3_ABC___'                                        │
│                                'Longname3:NU_2_CDE___'                                        │
│                                'Longname3:NU_2_CDE____delete'                                 │
╰───────────────────────────────────────────────────────────────────────────────────────────────╯
╭─ Options ─────────────────────────────────────────────────────────────────────────────────────╮
│ --help          Show this message and exit.                                                   │
╰───────────────────────────────────────────────────────────────────────────────────────────────╯

As for type ALL_PRODUCT_TYPES_T = Literal[... syntax - it's not supported yet. Let's use the following discussion to track that: #971