Python Reference

Getting Started with Python — installing Python, the interpreter (script mode vs. the interactive REPL), editors and IDEs, and the source-to-bytecode-to-PVM execution model.

Python IDEs & Tools — the IDEs, editors and notebook tools commonly used for Python.

Lexical Structure and Style — indentation-based blocks, comments and statement separators, PEP 8 naming and style, and the Zen of Python.

Variables and Dynamic Typing — names bound to objects, mutability, shared references and is vs. ==, and the built-in type hierarchy.

Numbers — int/float/complex, numeric operators, decimal/fractions for exact arithmetic, and the built-in numeric tools.

Strings and Text — string literals and slicing, common string methods, f-strings and other formatting, and str vs. bytes.

Collections — lists, tuples, sets, and dictionaries, their comprehensions, and when to choose each.

Control Flow — if/elif/else and truthiness, while/for loops, and the match statement.

Functions — parameters and return values, args/*kwargs and positional-/keyword-only markers, the LEGB scope rule, and lambda.

Iterators, Generators and Comprehensions — the iterator protocol, generator functions and expressions, and comprehensions revisited as sugar over iteration.

Modules and Packages — import forms, the name == "main" pattern, packages, and the module search path.

Files and Context Managers — open() and the with statement, and pathlib.Path as the modern alternative to os.path.

Exceptions — try/except/else/finally, exception chaining, custom exception hierarchies, and exception groups.

Classes and Objects — class basics, instance vs. class attributes, @staticmethod/@classmethod, and inheritance with super().

Operator Overloading — the common dunder methods for display, comparison, container behaviour, calling, context management, and arithmetic.

Advanced OOP Design — composition vs. inheritance, mixins and multiple inheritance, the Method Resolution Order, and delegation.

Managed Attributes — @property, the descriptor protocol, and getattr vs. getattribute.

Decorators and Metaclasses — function decorators, decorator factories and stacking, and a brief, cautious look at metaclasses.

Type Hints — basic annotations, generics and the modern X | None syntax, TypeVar/Protocol, and static checkers.

Dataclasses and Enums — @dataclass and its generated methods, and enum.Enum/IntEnum/Flag.

Standard Library Tour — filesystem/OS, data, math and random, and CLI/observability modules.

Concurrency and Async — threading, multiprocessing and concurrent.futures, and asyncio.

Virtual Environments and Packaging — venv, pip, and pyproject.toml.

Debugging and Tooling — pdb, timeit/cProfile, and linters and formatters.

Docstrings — what docstrings are, common style conventions (Google, NumPy, reST, Epytext), and generating static documentation sites with Sphinx, pdoc, and MkDocs.

Build Automation Tools (pip & Poetry) — the shared concepts: packaging standards, pyproject.toml, version specifiers, environments, lock files, supply-chain security, CI caching and containers, and choosing between pip and Poetry.

pip — the standard installer from installation to resolution, indexes, configuration, hash-checked installs, pip lock and troubleshooting.

Poetry — dependency management and packaging with Poetry 2, from installation and poetry.lock to plugins, configuration and the migration from 1.x.

Publishing & Distributing Libraries — preparing, versioning, building, checking and publishing a library to PyPI and private indexes, with Trusted Publishing and attestations.

Unit Testing with pytest & Mocking — test discovery, fixtures, parametrization, and mocking with unittest.mock and monkeypatch.

Cheat Sheet (PDF) — a single-page, printable summary of everything in this section, with a downloadable PDF.

pip documentation — getting started, installation, user guide, topic guides, reference and CLI pages; changelog and release process.

pip source code — for the exact error messages.

Poetry documentation — every page; history; blog (the release posts for 1.2.0 to 2.5.0).

poetry-core; the installer install.python-poetry.org and its repository.

Plugins: poetry-plugin-export, poetry-plugin-shell, poetry-plugin-bundle.

Poetry source code — for the lock file format and exact error messages.

Python Packaging User Guide — tutorials, guides, discussions, specifications and key projects.

PEPs: 427 (wheel format), 440 (versions), 503 (simple repository API), 508 (dependency specifiers), 517 (build backends), 518 (build requirements), 592 (yanking), 610 (direct URL origin), 621 (project metadata), 625 (sdist file names), 639 (license metadata), 643 (sdist metadata), 658 (metadata in the simple API), 660 (editable installs), 668 (externally managed environments), 685 (extra names), 691 (JSON simple API), 723 (inline script metadata), 735 (dependency groups), 740 (attestations), 751 (pylock.toml), 770 (SBOMs), 792 (project status markers), 794 (import name metadata), 808 (static values in dynamic metadata) and 833 (freezing the HTML simple API); also 561, 600 and 803 where pages use them.

Status of Python versions.

PyPI documentation — trusted publishers, attestations, publishing, project management, account and API pages; PyPI help; PyPI blog (the posts cited); TestPyPI.

build, twine, pypa/gh-action-pypi-publish, cibuildwheel.

Backends: setuptools, setuptools-scm, Hatch and hatchling, Flit, pdm-backend, the uv build backend, scikit-build-core, meson-python, maturin.

CI: actions/setup-python and the GitHub Actions Python tutorial; the GitLab PyPI package registry.

TOML, the SPDX License List, Semantic Versioning, Calendar Versioning, OpenID Connect, Sigstore, in-toto attestations, SLSA, SOURCE_DATE_EPOCH, CycloneDX.

uv, pip-tools, pipx, virtualenv, PDM, Pipenv, tox, nox, nox-poetry, pre-commit, pip-audit, check-wheel-contents, hynek/build-and-inspect-python-package.

Indexes and registries: pypiserver, devpi, Sonatype Nexus, JFrog Artifactory, AWS CodeArtifact, Azure Artifacts, Google Artifact Registry, conda-forge.

Download statistics: pypinfo, ClickPy.