Python

Python is a dynamically-typed, general-purpose language that dominates AI/ML, data engineering, and modern backend. Created by Guido van Rossum in 1991, Python 3.12+ in 2026 is the default choice for building anything from a 50-line data script to a production API serving millions of requests, and for every LLM-backed application from LangChain agents to Stripe-style AI receipt parsers. At every level from Beginner to Expert, Python rewards depth. Beginners ship working code in days; seniors build type-safe async systems with FastAPI, SQLAlchemy 2.x, and Pydantic v2; experts understand the GIL, metaclasses, and C extension authoring. This page covers the full arc — one skill, four levels, twelve months to senior.