Pydantic on Manvendra Rajpoot https://blog.rajpoot.dev/tags/pydantic/ Recent content in Pydantic on Manvendra Rajpoot Manvendra Rajpoot https://blog.rajpoot.dev/img/personal/cover.png https://blog.rajpoot.dev/img/personal/cover.png Hugo en Manvendra Rajpoot Sun, 17 May 2026 17:50:46 +0530 Integration Cheatsheet 01 — Full-Stack Project Skeleton https://blog.rajpoot.dev/cheatsheets/integrations/01-full-stack-skeleton-cheatsheet/ Sat, 16 May 2026 06:00:00 +0530 https://blog.rajpoot.dev/cheatsheets/integrations/01-full-stack-skeleton-cheatsheet/ FastAPI + SQLAlchemy + Pydantic + Alembic project skeleton. Pydantic Cheatsheet 01 — BaseModel Basics https://blog.rajpoot.dev/cheatsheets/pydantic/01-basemodel-cheatsheet/ Thu, 14 May 2026 06:00:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/01-basemodel-cheatsheet/ Pydantic v2 BaseModel cheatsheet — definition, validation, serialization. Pydantic v2 Textbook Ch. 1 — Introduction and the v2 Mental Model https://blog.rajpoot.dev/textbooks/pydantic/01-introduction-and-mental-model/ Sat, 09 May 2026 06:00:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/01-introduction-and-mental-model/ Chapter 1 — Pydantic v2 introduction: BaseModel, validation vs serialization, the v2 architecture. Pydantic Cheatsheet 02 — Field and Constraints https://blog.rajpoot.dev/cheatsheets/pydantic/02-fields-constraints-cheatsheet/ Thu, 14 May 2026 06:10:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/02-fields-constraints-cheatsheet/ Pydantic v2 Field cheatsheet — defaults, constraints, descriptions, aliases. FastAPI Cheatsheet 02 — Pydantic Request Validation https://blog.rajpoot.dev/cheatsheets/fastapi/02-pydantic-validation-cheatsheet/ Mon, 11 May 2026 06:10:00 +0530 https://blog.rajpoot.dev/cheatsheets/fastapi/02-pydantic-validation-cheatsheet/ FastAPI request validation cheatsheet — Pydantic v2 models, validators, error handling, recipes. Pydantic v2 Textbook Ch. 2 — Fields, Types, and Constraints https://blog.rajpoot.dev/textbooks/pydantic/02-fields-types-constraints/ Sat, 09 May 2026 06:10:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/02-fields-types-constraints/ Chapter 2 — Pydantic v2 fields, types, constraints, defaults, aliases. Integration Cheatsheet 03 — Pydantic ↔ SQLAlchemy Mapping https://blog.rajpoot.dev/cheatsheets/integrations/03-pydantic-sqlalchemy-mapping-cheatsheet/ Sat, 16 May 2026 06:20:00 +0530 https://blog.rajpoot.dev/cheatsheets/integrations/03-pydantic-sqlalchemy-mapping-cheatsheet/ Map Pydantic schemas to SQLAlchemy models — Read/Create/Update, from_attributes. Pydantic Cheatsheet 03 — Validators https://blog.rajpoot.dev/cheatsheets/pydantic/03-validators-cheatsheet/ Thu, 14 May 2026 06:20:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/03-validators-cheatsheet/ Pydantic v2 validators — field_validator, model_validator, before/after, Annotated validators. Pydantic v2 Textbook Ch. 3 — Validators in Depth https://blog.rajpoot.dev/textbooks/pydantic/03-validators/ Sat, 09 May 2026 06:20:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/03-validators/ Chapter 3 — Pydantic v2 validators: field_validator, model_validator, before/after, BeforeValidator/AfterValidator. FastAPI Textbook Ch. 3 — Pydantic Models and Request Validation https://blog.rajpoot.dev/textbooks/fastapi/03-pydantic-models-validation/ Wed, 06 May 2026 06:20:00 +0530 https://blog.rajpoot.dev/textbooks/fastapi/03-pydantic-models-validation/ Chapter 3 — Pydantic for FastAPI: input models, validators, types, custom errors, and how request bodies become typed Python objects. Pydantic Cheatsheet 04 — Serialization https://blog.rajpoot.dev/cheatsheets/pydantic/04-serialization-cheatsheet/ Thu, 14 May 2026 06:30:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/04-serialization-cheatsheet/ Pydantic v2 serialization — model_dump, custom serializers, mode. Pydantic v2 Textbook Ch. 4 — Serialization in Depth https://blog.rajpoot.dev/textbooks/pydantic/04-serialization/ Sat, 09 May 2026 06:30:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/04-serialization/ Chapter 4 — Pydantic v2 serialization: model_dump, model_dump_json, custom serializers, exclude, mode. Pydantic Cheatsheet 05 — Discriminated Unions and Generics https://blog.rajpoot.dev/cheatsheets/pydantic/05-discriminated-unions-cheatsheet/ Thu, 14 May 2026 06:40:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/05-discriminated-unions-cheatsheet/ Pydantic v2 discriminated unions, generic models, recursion. Pydantic v2 Textbook Ch. 5 — Nested Models, Generics, and Discriminated Unions https://blog.rajpoot.dev/textbooks/pydantic/05-nested-generics-unions/ Sat, 09 May 2026 06:40:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/05-nested-generics-unions/ Chapter 5 — Pydantic v2: nested models, generic models, discriminated unions. Pydantic Cheatsheet 06 — Custom Types and TypeAdapter https://blog.rajpoot.dev/cheatsheets/pydantic/06-custom-types-cheatsheet/ Thu, 14 May 2026 06:50:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/06-custom-types-cheatsheet/ Pydantic v2 custom types, TypeAdapter, dataclass integration. Pydantic v2 Textbook Ch. 6 — Custom Types and TypeAdapter https://blog.rajpoot.dev/textbooks/pydantic/06-custom-types-typeadapter/ Sat, 09 May 2026 06:50:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/06-custom-types-typeadapter/ Chapter 6 — Pydantic v2 custom types, RootModel, TypeAdapter, dataclass integration. Pydantic Cheatsheet 07 — Strict vs Lax Mode https://blog.rajpoot.dev/cheatsheets/pydantic/07-strict-lax-cheatsheet/ Thu, 14 May 2026 07:00:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/07-strict-lax-cheatsheet/ Pydantic v2 strict / lax mode — coercion rules, per-field strict, per-call strict. Pydantic v2 Textbook Ch. 7 — Strict Mode and Coercion https://blog.rajpoot.dev/textbooks/pydantic/07-strict-mode-coercion/ Sat, 09 May 2026 07:00:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/07-strict-mode-coercion/ Chapter 7 — Pydantic v2 strict mode, lax mode, per-field strict types, and coercion rules. Pydantic Cheatsheet 08 — Aliases (Input/Output Field Names) https://blog.rajpoot.dev/cheatsheets/pydantic/08-aliases-cheatsheet/ Thu, 14 May 2026 07:10:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/08-aliases-cheatsheet/ Pydantic v2 aliases — alias, validation_alias, serialization_alias, AliasChoices, AliasPath. Pydantic v2 Textbook Ch. 8 — JSON Schema Generation https://blog.rajpoot.dev/textbooks/pydantic/08-json-schema/ Sat, 09 May 2026 07:10:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/08-json-schema/ Chapter 8 — Pydantic v2 JSON Schema generation, OpenAPI integration, custom schemas. Pydantic Cheatsheet 09 — pydantic-settings https://blog.rajpoot.dev/cheatsheets/pydantic/09-settings-cheatsheet/ Thu, 14 May 2026 07:20:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/09-settings-cheatsheet/ pydantic-settings cheatsheet — env vars, .env, secrets, layered config. Pydantic v2 Textbook Ch. 9 — Settings (pydantic-settings) https://blog.rajpoot.dev/textbooks/pydantic/09-settings/ Sat, 09 May 2026 07:20:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/09-settings/ Chapter 9 — pydantic-settings: env vars, .env files, secrets, layered config, CLI integration. Pydantic Cheatsheet 10 — JSON Schema and OpenAPI https://blog.rajpoot.dev/cheatsheets/pydantic/10-json-schema-cheatsheet/ Thu, 14 May 2026 07:30:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/10-json-schema-cheatsheet/ Pydantic v2 JSON Schema generation — model_json_schema, OpenAPI, LLM tool calling. Pydantic v2 Textbook Ch. 10 — Performance, FastAPI Integration, and Alternatives https://blog.rajpoot.dev/textbooks/pydantic/10-performance-and-alternatives/ Sat, 09 May 2026 07:30:00 +0530 https://blog.rajpoot.dev/textbooks/pydantic/10-performance-and-alternatives/ Chapter 10 — Pydantic performance, FastAPI integration patterns, and alternatives (msgspec, attrs). Pydantic Cheatsheet 11 — Performance https://blog.rajpoot.dev/cheatsheets/pydantic/11-performance-cheatsheet/ Thu, 14 May 2026 07:40:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/11-performance-cheatsheet/ Pydantic v2 performance tips — schema caching, TypeAdapter, validation speed, msgspec comparison. Pydantic Cheatsheet 12 — Error Handling https://blog.rajpoot.dev/cheatsheets/pydantic/12-errors-cheatsheet/ Thu, 14 May 2026 07:50:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/12-errors-cheatsheet/ Pydantic v2 ValidationError — structure, formatting, custom error envelopes. Pydantic Cheatsheet 13 — ORM Mode (from_attributes) https://blog.rajpoot.dev/cheatsheets/pydantic/13-orm-mode-cheatsheet/ Thu, 14 May 2026 08:00:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/13-orm-mode-cheatsheet/ Pydantic v2 from_attributes — converting SQLAlchemy / attrs / dataclass instances. Pydantic Cheatsheet 14 — FastAPI Patterns https://blog.rajpoot.dev/cheatsheets/pydantic/14-fastapi-patterns-cheatsheet/ Thu, 14 May 2026 08:10:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/14-fastapi-patterns-cheatsheet/ Pydantic + FastAPI common patterns — request/response models, partial updates, query class. Pydantic Cheatsheet 15 — Recursive Models and Forward References https://blog.rajpoot.dev/cheatsheets/pydantic/15-recursive-models-cheatsheet/ Thu, 14 May 2026 08:20:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/15-recursive-models-cheatsheet/ Pydantic v2 recursive models, forward refs, mutually-recursive models. Pydantic Cheatsheet 16 — Computed Fields https://blog.rajpoot.dev/cheatsheets/pydantic/16-computed-fields-cheatsheet/ Thu, 14 May 2026 08:30:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/16-computed-fields-cheatsheet/ Pydantic v2 computed_field — derived attributes in output. Pydantic Cheatsheet 17 — pydantic.dataclasses https://blog.rajpoot.dev/cheatsheets/pydantic/17-dataclass-cheatsheet/ Thu, 14 May 2026 08:40:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/17-dataclass-cheatsheet/ Pydantic v2 dataclass integration — when to use, when to skip. Pydantic Cheatsheet 18 — Common Domain Types (IDs, Money, Phone, Email) https://blog.rajpoot.dev/cheatsheets/pydantic/18-common-domain-types-cheatsheet/ Thu, 14 May 2026 08:50:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/18-common-domain-types-cheatsheet/ Pydantic v2 common domain types — IDs, money, phone numbers, dates, URLs. Pydantic Cheatsheet 19 — Testing Pydantic Models https://blog.rajpoot.dev/cheatsheets/pydantic/19-testing-cheatsheet/ Thu, 14 May 2026 09:00:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/19-testing-cheatsheet/ Pydantic testing patterns — parametrized validation tests, factories, error matching. Pydantic Cheatsheet 20 — Migration v1 → v2 https://blog.rajpoot.dev/cheatsheets/pydantic/20-migration-v1-v2-cheatsheet/ Thu, 14 May 2026 09:10:00 +0530 https://blog.rajpoot.dev/cheatsheets/pydantic/20-migration-v1-v2-cheatsheet/ Pydantic v1 → v2 migration cheatsheet — renames, API differences, gotchas. Pydantic v2 Deep Dive — The Patterns Every Backend Python Developer Needs https://blog.rajpoot.dev/posts/python/pydantic-v2-deep-dive-2026/ Thu, 30 Apr 2026 11:00:00 +0530 https://blog.rajpoot.dev/posts/python/pydantic-v2-deep-dive-2026/ A deep dive into Pydantic v2 — model design, validators, serializers, settings, performance, and the patterns that make it the typed-data backbone of modern Python. Structured Output for LLMs in 2026 — Pydantic AI, Instructor, and the End of JSON Parsing https://blog.rajpoot.dev/posts/ai/structured-output-pydantic-ai-instructor-2026/ Thu, 30 Apr 2026 09:10:00 +0530 https://blog.rajpoot.dev/posts/ai/structured-output-pydantic-ai-instructor-2026/ How to get structured, validated output from LLMs in 2026 — Pydantic AI, Instructor, native tool-calling, OpenAI's structured outputs API, and the patterns that make extraction reliable. FastAPI + Pydantic v2 + SQLAlchemy 2.0 — Production Patterns for 2026 https://blog.rajpoot.dev/posts/fastapi/fastapi-pydantic-v2-sqlalchemy-2-production/ Tue, 28 Apr 2026 17:00:00 +0530 https://blog.rajpoot.dev/posts/fastapi/fastapi-pydantic-v2-sqlalchemy-2-production/ The FastAPI stack worth building on in 2026 — Pydantic v2, async SQLAlchemy 2.0, dependency injection, settings, errors, observability, and the layout that scales past one file. Getting Started with FastAPI: Modern Python APIs Done Right https://blog.rajpoot.dev/posts/fastapi/getting-started-with-fastapi/ Tue, 28 Apr 2026 11:00:00 +0530 https://blog.rajpoot.dev/posts/fastapi/getting-started-with-fastapi/ A practical introduction to FastAPI — the async Python framework that gives you type-safe APIs, automatic docs, and great performance with very little ceremony.