It's not possible to use Pydantic BaseSettings with a package called with Typer CLI

Copied original issue from: https://github.com/tiangolo/typer/issues/91

---

Describe the bug

I am using typer as a package where I get the following error

  .
  .
  File "/root/typer_app/main.py", line 9, in publish
    class Settings(BaseSettings):
  File "pydantic/main.py", line 184, in pydantic.main.ModelMetaclass.__new__
  File "pydantic/typing.py", line 136, in pydantic.typing.resolve_annotations
    if arg is None:
KeyError: 'typer_app.main'

To Reproduce

I am using typer as a package

/root
| typer_app
  | __init__.py
  | main.py

where

main.py

import typer
from pydantic import BaseSettings

app = typer.Typer()


@app.command()
def publish():
    class Settings(BaseSettings):
        HTTP_ENDPOINT: str

    settings = Settings()
    typer.echo(settings.HTTP_ENDPOINT)

• Call it with:

PYTHONPATH=/root typer typer_app.main run

• It outputs:

  .
  .
  File "/root/typer_app/main.py", line 9, in publish
    class Settings(BaseSettings):
  File "pydantic/main.py", line 184, in pydantic.main.ModelMetaclass.__new__
  File "pydantic/typing.py", line 136, in pydantic.typing.resolve_annotations
    if arg is None:
KeyError: 'typer_app.main'

• But I expected it to output a validation error since HTTP_ENDPOINT is not set.

Environment

Linux Mint - Python 3.8.2
typer==0.1.1
typer-cli==0.0.8

[kbanc]

Can I look into this?

[kbanc]

@tiangolo I wasn’t able to get around to looking at the issue this week! If anyone else is interested in working on it, please be my guest 😃