Pydantic v2 Patterns

Validation, serialization, and settings management with Pydantic v2.

When to Activate

• Defining request/response schemas or domain models
• Writing @field_validator or @model_validator for custom validation
• Using Annotated to build reusable constrained types
• Controlling serialization with model_dump() / model_dump_json()
• Building generic models or discriminated unions
• Validating arbitrary data (not a model) with TypeAdapter
• Configuring app settings from environment variables with pydantic-settings

BaseModel Basics