#Python
147 posts
Authentication — OAuth2 password flow + JWT
Password hashing (argon2/bcrypt), the OAuth2 password flow, JWT issuance/verification, and the current_user dependency that wraps it all into a clean auth pattern.
Building CLI tools (Typer)
How to build a type-hints-first CLI with Typer instead of argparse. Subcommands, autocompletion, and Rich-powered output.
Capstone — finishing the TODO API
Tie the patterns from Chapters 1 ~ 28 into a single working service. Authenticated per-user TODO CRUD, tag filtering, pagination, background notifications, tests, and deploy.
Collections and comprehensions
The four collections — list/tuple/dict/set — and the comprehensions and generator expressions that build new collections in one line.
Connecting a DB — SQLAlchemy 2.x + Alembic
SQLAlchemy 2.x's new style — Mapped/mapped_column, async sessions, integration with FastAPI's dependency injection, and Alembic migrations.
Context managers (with, contextlib)
with that turns try/finally into one line, building your own with __enter__/__exit__, @contextmanager for constructor-short forms, and practical tools like ExitStack/suppress.
Control flow — if, while, for, match-case
Flow control where blocks come from indentation, range/enumerate/zip, and match-case pattern matching that differs in feel from switch.
dataclass and __slots__
Every option of @dataclass for short, safe data classes — frozen, kw_only, field() — plus __slots__ for memory savings, all in one place.
Decorator patterns
Every shape of decorator that wraps a function — the basic form, decorators with arguments, functools.wraps, class decorators, and ParamSpec.
Descriptors and __set_name__
How property works — the __get__/__set__ protocol and data/non-data descriptors, and clean validation fields with __set_name__.
Errors and exception handling
The roles of try/except/else/finally, raise and user-defined exceptions, and the ExceptionGroup and except* introduced in 3.11.
FastAPI setup and getting started
Why FastAPI, first project setup with uv, Hello FastAPI, automatic OpenAPI/Swagger UI generation — all in one place.