Python Code
110 interactive Python concept pages across 12 sections.
Each page shows broken code — predict the output, then reveal what actually happens and why.
Setup & Execution
Virtual environments, package managers, module resolution, pytest, and how CPython actually executes your code.
Loops, Functions & Scopes
Comprehensions, generators, closures, LEGB scope rules, and the lesser-known function features every Python dev should know.
Memory & Data Structures
Object model, mutability, copy semantics, identity vs equality, and the internals of Python's core data structures.
Modern OOP
Dataclasses, type hints, Pydantic, protocols, descriptors, and modern Python class patterns for clean, maintainable code.
Python's Hidden Traps
Subtle bugs and surprising behaviors — mutable defaults, late binding, integer interning, and the pitfalls that catch experienced devs off guard.
Async Python
The GIL, asyncio, concurrency vs parallelism, event loops, and how to write correct async Python without blocking the world.
FastAPI
Path parameters, dependency injection, Pydantic models, middleware, WebSockets, lifespan, and testing patterns in FastAPI.
Databases
SQLAlchemy ORM and Core, Alembic migrations, session management, the N+1 problem, connection pooling, and vector databases.
Pandas & Data
DataFrame internals, Copy-on-Write, chained indexing traps, vectorized operations, groupby patterns, and Pandas 2.0 changes.
AI Agents & LLM Apps
LLM API basics, RAG pipelines, embeddings, function calling, streaming, context window management, and LLM evaluation.
Deployment & Monitoring
Docker, Dockerfiles, GitHub Actions CI/CD, structured logging, OpenTelemetry, health checks, and graceful shutdown patterns.
Performance & Security
Profiling, bottleneck identification, __slots__, Cython basics, AST manipulation, OWASP concerns for Python, bandit, and dependency auditing.