Reading settings with Pydantic

settings_with_pydantic.py

import os
import pytest
from pydantic import BaseSettings, HttpUrl, ValidationError


class Config(BaseSettings):  # 1, 2
    auth_url: HttpUrl
    db_name: str
    max_retries: int

def test_read_and_parse_env_vars():
    os.environ.clear()
    os.environ['auth_url'] = 'http://www.weird.auth.name.com'
    os.environ['db_name'] = 'mydb'
    os.environ['max_retries'] = '7'

    config = Config()  # 3

    assert config.auth_url == 'http://www.weird.auth.name.com'
    assert config.db_name == 'mydb'
    assert config.max_retries == 7


def test_all_errors_appear_together():
    os.environ.clear()
    os.environ['auth_url'] = 'not a url'
    os.environ['max_retries'] = 'not an int'

    with pytest.raises(ValidationError) as e:  # 4
        Config()  # 3

    assert 'auth_url' in str(e.value)  # 5
    assert 'max_retries' in str(e.value)  # 5
    assert 'db_name' in str(e.value)  # 5