Packages
Provides decorators to automate deprecation warnings, update docstrings with deprecation details, and enforce removal deadlines in tests.
Beartype is a runtime type checker that validates Python type hints at function call time, catching type violations before they cause downstream bugs.
Install it if you want runtime type safety for your annotated code or need to validate type hints on third-party packages.
Tomli-W serializes Python dictionaries to TOML format strings or files, providing a write-only counterpart to TOML parsing.
Install it if you need to write TOML files from Python.
Pathable provides path-like objects for traversing nested data structures (dicts, lists, and other subscriptable trees) using familiar `/` syntax, with safe and strict access patterns.
FastUUID provides CPython bindings to Rust's UUID library, offering faster UUID generation and parsing than Python's standard library with support for UUID versions 1, 3, 4, 5, and 7.
Provides Python bindings to the Brotli compression library, enabling lossless compression and decompression using a modern LZ77 variant with Huffman coding and context modeling.
Install it if you need Brotli compression in Python; the API is straightforward and the library is battle-tested.
Extends markdown-it-py with a collection of core plugins for additional markdown syntax and rendering capabilities.
Install it if you are using markdown-it-py and need the specific plugins it provides.
Measures cyclomatic complexity of Python functions and integrates with flake8 to flag overly complex code during linting.
Install it if you use flake8 and want to enforce complexity limits, or if you need a standalone complexity scanner.
Extracts and queries package metadata from source distributions (sdists), binary distributions (wheels, eggs), and installed packages by reading PKG-INFO, EGG-INFO, or dist-info files.
Install it if you need to programmatically extract or inspect package metadata from distributions or installed packages.
Parse, compare, and manipulate semantic version strings following the MAJOR.MINOR.PATCH format, with support for pre-release and build metadata.
Install it if you need to work with version strings programmatically.
xlrd reads data and formatting information from legacy Excel .xls files, extracting cell values, sheet metadata, and formula results without support for newer formats or advanced features like macros, charts, or password protection.
However, note that it is aging (last release 426 days ago) and does not support newer Excel formats—if you work primarily with .xlsx or .xlsm files, look elsewhere.
onnxruntime loads and executes Open Neural Network Exchange (ONNX) models with a focus on inference performance across CPUs and accelerators.
Install it if you have ONNX models to run in production or development.
pycodestyle checks Python code against PEP 8 style conventions, reporting violations with line and column numbers for editor integration.
Converts Unicode text to ASCII by transliterating non-ASCII characters into their closest ASCII equivalents, with no runtime dependencies.
However, if transliteration quality or ongoing maintenance matters, consider unidecode instead despite its GPL-only license.
Detects and extracts URLs, email addresses, and custom protocol links from plain text with full Unicode support, including international domains and astral characters.
Rich Toolkit provides opinionated CLI application components built on Rich, offering styled context managers and utilities for consistent command-line interfaces.
However, verify that the toolkit's design opinions and component set match your specific CLI needs before committing, as the documentation appears incomplete in the…
Provides a C-based YAML 1.2 reader, parser, and emitter derived from libyaml, offering faster performance than pure Python implementations.
Invoke is a Python library for defining and running shell commands and executable Python code as CLI-invokable tasks, with subprocess management and task organization.
Install it if you need to organize shell commands and Python code into CLI tasks without the overhead of larger frameworks or shell scripting.
Provides a minimal Unicode data subset for linkify-it-py projects, supplying essential Unicode character classifications needed for URL and email detection.
Poetry is a dependency management and packaging tool that replaces setup.py, requirements.txt, and similar files with a single pyproject.toml configuration, handling project dependencies, virtual environments, and package builds.
Install it if you want deterministic dependency management and modern packaging practices.
Provides bash and zsh tab completion for Python applications using argparse, allowing users to complete command-line arguments and options by pressing Tab.
Install it if you want to add professional-grade tab completion to your Python command-line tools.
Faker generates realistic fake data—names, addresses, emails, phone numbers, and more—for testing, database bootstrapping, and data anonymization across multiple locales.
Install it if you need realistic fake data for tests, prototyping, or anonymization; skip it only if you have no use for generated test data.
Arrow provides a simpler, more intuitive API for creating, manipulating, formatting, and converting dates, times, and timestamps in Python, with built-in timezone awareness and ISO 8601 support.
Install it if you work with dates and times frequently and want cleaner, less verbose code.
Cleo builds command-line interfaces with argument and option parsing, colored output, and verbosity control, using two lightweight runtime dependencies (crashtest and rapidfuzz).
Lark is a parsing library that builds abstract syntax trees from context-free grammars, supporting multiple parsing algorithms (Earley, LALR(1), CYK) with automatic line and column tracking.
Snowflake SQLAlchemy is a SQLAlchemy dialect that enables SQLAlchemy applications to connect to and query Snowflake databases using standard SQLAlchemy ORM and Core APIs.
Install it if you are building a Python application that needs to connect to Snowflake and prefer SQLAlchemy's abstraction layer over raw SQL or the connector API.
Bleach sanitizes untrusted HTML by escaping or stripping markup and attributes against an allowed list, and can safely linkify URLs in text.
FastAPI CLI is a command-line tool that runs and manages FastAPI applications, automatically detecting and serving your app with development or production modes via `fastapi dev` and `fastapi run` commands.
Install it if you are building FastAPI applications.
Provides low-level CFFI bindings to the official Argon2 password hashing algorithm for use by libraries and applications that need direct access to Argon2 without higher-level abstractions.
Provides additional type validators and serializers for Pydantic v2 that are too specialized or niche for the main library, extending Pydantic's type system with domain-specific types.
Install only if you actually need one of its specialized types; it's not a general-purpose enhancement.
Portalocker provides cross-platform file locking with support for exclusive and shared locks, plus Redis-based distributed locks and process-aware PID file locking.
Install it if you need file or process coordination; the optional extras (pywin32, redis) are only required for specific lock types.
Provides a high-performance Python client for Apache Kafka that wraps librdkafka, offering Producer, Consumer, and AdminClient APIs with support for transactions, schema integration, and asyncio.
simplejson encodes Python objects to JSON and decodes JSON strings back to Python objects, with optional C acceleration and support for custom serialization and deserialization hooks.
Install it if you need JSON serialization with custom hooks or must support Python 2.7; otherwise the standard library's json module is sufficient for most use cases.
Flask-CORS handles Cross-Origin Resource Sharing (CORS) headers in Flask applications, enabling safe cross-origin AJAX requests with configurable per-route or application-wide policies.
Install it if you need CORS support in a Flask application.
grpclib is a pure-Python asyncio-based implementation of gRPC that lets you build asynchronous client and server applications using protocol buffers for serialization.
PostgreSQL database adapter for Python that implements the DB API 2.0 specification, enabling thread-safe connections, cursors, and SQL execution with native support for PostgreSQL data types.
Kombu is a messaging library that provides a high-level Python interface to AMQP and other message brokers, supporting pluggable transports for RabbitMQ, Redis, MongoDB, Amazon SQS, and others.
Install it if you are building any distributed system that requires reliable message passing.
Flake8 is a command-line tool that combines PyFlakes, pycodestyle, and McCabe to check Python code for style violations, logical errors, and complexity issues in a single pass.
Provides type annotations and IDE code completion for the awscrt package, enabling static type checking with mypy or pyright.
Provides Google's production-tested Python utility libraries for application startup, distributed command-line flags, custom logging, and testing utilities.