pydantic-typer 0.0.4

Typer extension to enable pydantic support

Pydantic Typer

Typer extension to enable pydantic support

[!WARNING]
This package is still in early development and some things might not work as expected, or change between versions.

---

Table of Contents

• Installation
• Usage
• License

Installation

pip install pydantic-typer

[!NOTE] > pydantic-typer comes with pydantic and typer as dependencies, so you don't need to install anything else.

Usage

For general typer usage, please refer to the typer documentation.

All the code blocks below can be copied and used directly (they are tested Python files). To run any of the examples, copy the code to a file main.py, and run it:

python main.py

Basic Usage

Simply add the @enable_pydantic decorator to any function that you use with typer.run:

import pydantic
import typer

from pydantic_typer import enable_pydantic


class User(pydantic.BaseModel):
    id: int
    name: str = "Jane Doe"


@enable_pydantic
def main(num: int, user: User):
    print(num, type(num))
    print(user, type(user))


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

Usage with nested models

@enable_pydantic also works with nested pydantic models:

from __future__ import annotations

from typing import Optional

import pydantic
import typer

from pydantic_typer import enable_pydantic


class Pet(pydantic.BaseModel):
    name: str
    species: str


class Person(pydantic.BaseModel):
    name: str
    age: Optional[float] = None  # noqa: UP007 typer does not support float | None yet, see https://github.com/tiangolo/typer/pull/548
    pet: Pet


@enable_pydantic
def main(person: Person):
    print(person, type(person))


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

Use pydantic models with typer.Argument

You can annotate the parameters with typer.Argument to make all model fields CLI arguments:

from __future__ import annotations

import pydantic
import typer
from typing_extensions import Annotated

from pydantic_typer import enable_pydantic


class User(pydantic.BaseModel):
    id: int
    name: str


@enable_pydantic
def main(num: Annotated[int, typer.Option()], user: Annotated[User, typer.Argument()]):
    print(num, type(num))
    print(user, type(user))


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

:bulb: You can also override annotations directly on the pydantic model fields:

from __future__ import annotations

import pydantic
import typer
from typing_extensions import Annotated

from pydantic_typer import enable_pydantic


class User(pydantic.BaseModel):
    id: Annotated[int, typer.Argument(metavar="THE_ID")]
    name: Annotated[str, typer.Option()]


@enable_pydantic
def main(num: Annotated[int, typer.Option()], user: Annotated[User, typer.Argument()]):
    print(num, type(num))
    print(user, type(user))


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

Here, User is a typer.Argument, but we manually override the fields again:

• We override the metavar of to User.id be THE_ID
• And User.name to be a typer.Option

Use pydantic models in multiple commands

For larger typer apps, you can use pydantic_typer.PydanticTyper instead of annotating each command function individually to enable pydantic models on all commands:

from __future__ import annotations

import pydantic
import typer
from typing_extensions import Annotated

from pydantic_typer import PydanticTyper

app = PydanticTyper()


class User(pydantic.BaseModel):
    id: int
    name: Annotated[str, typer.Option()] = "John"


@app.command()
def hi(user: User):
    print(f"Hi {user}")


@app.command()
def bye(user: User):
    print(f"Bye {user}")


if __name__ == "__main__":
    app()

Use pydantic types

You can also annotate arguments with pydantic types and they will be validated:

import click
import typer
from pydantic import HttpUrl, conint

from pydantic_typer import enable_pydantic_type_validation

EvenInt = conint(multiple_of=2)


@enable_pydantic_type_validation
def main(num: EvenInt, url: HttpUrl, ctx: click.Context):  # type: ignore
    print(num, type(num))
    print(url, type(url))


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

License

pydantic-typer is distributed under the terms of the MIT license.