How to read ENVs with pydantic.BaseSettings

read_envs_pydantic_basesettings.py

from pydantic import BaseSettings, Field, SecretStr


class Credentials(BaseSettings):
    password: SecretStr = Field(..., env="DB_PASSWORD")


"""
>>> Credentials()
pydantic.error_wrappers.ValidationError: 1 validation error for Credentials
password
  field required (type=value_error.missing)

>>> os.environ['DB_PASSWORD'] = 'admin'
>>> Credentials()
Credentials(password=SecretStr('**********'))

>>> Credentials(password='adminadmin')
Credentials(password=SecretStr('**********'))
"""

dependencies: python3.9, pydantic==1.9.2