Chapter 10: Configuration and Settings

ASP.NET Core has layered configuration providers and options binding. Python commonly uses environment variables with a typed settings class.

from pydantic import Field
from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env",
        env_prefix="RECIPEVAULT_",
        extra="ignore",
    )

    app_name: str = "RecipeVault"
    database_url: str = Field(default="sqlite:///recipevault.db")
    secret_key: str
    debug: bool = False

Rules:

• Treat settings as immutable values at app startup.
• Never commit real secrets.
• Use .env only for local development.
• In production, use the host's secret manager or environment injection.
• Fail fast when required settings are missing.
• Keep framework settings separate from domain configuration.

Configuration is one area where Python is more fragmented than .NET. Pick one settings approach and use it everywhere.