Packages
Creates interactive command-line menus where users select options using arrow keys, vim motions, or keyboard shortcuts, with built-in search and multi-select support.
Provides a straightforward WebSocket server and client implementation for Python, handling the WebSocket protocol over a single runtime dependency.
Install it if you need straightforward WebSocket functionality without framework overhead.
Evaluates mathematical and logical expressions from strings in a safe, sandboxed way without using Python's built-in eval(), letting you add user-configurable formulas to applications.
Install it if you need to evaluate untrusted formulas; avoid it only if you need features beyond basic arithmetic, comparisons, and simple function calls, or if…
Simplefix provides a lightweight FIX (Financial Information eXchange) protocol implementation for creating, encoding, and decoding FIX messages used in financial trading systems.
Install it if you need to work with FIX messages in Python and want a lightweight alternative to a full FIX engine.
Simpleflow provides a Python library for writing distributed dataflow programs that coordinate task execution through Amazon SWF, using a futures-based abstraction to define task dependencies.
Provides a lightweight decorator-based system for defining single-dispatch generic functions that route calls based on the type or identity of their first argument.
Install only if you are maintaining legacy code that already depends on it and cannot migrate to functools.singledispatch.
A Python wrapper around the Gmail API that handles authentication, sending messages with attachments, retrieving and searching emails, and managing labels and message state.
However, be aware that oauth2client is deprecated by Google; if you need active development or modern auth practices, consider evaluating google-auth-based…
SimpleITK provides a simplified Python interface to the Insight Toolkit (ITK) for performing image segmentation, registration, and general filtering operations on 2D, 3D, and 4D images.
Encodes and decodes JPEG images directly to and from memory using libturbojpeg, with support for multiple colorspaces and fast header inspection.
Not recommended if you need a lightweight pure-Python solution or broad format support beyond JPEG.
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.
Simplekml generates KML (Keyhole Markup Language) files for geographic data visualization with minimal code, supporting basic elements like points, lines, polygons, folders, and documents.
However, its abandoned status (no updates since 2021) means it will not adapt to future KML standard changes or Python version incompatibilities.
simplekv provides a unified key-value storage API that abstracts over multiple backends—filesystem, SQLAlchemy, MongoDB, Redis, S3, and Google Storage—letting you swap storage implementations without changing application code.
Simplemma converts inflected word forms to their dictionary base forms (lemmas) across 54 languages using pure Python with no external dependencies or model downloads.
Install it for baseline NLP work, teaching, or low-resource settings; do not install it if you need the highest accuracy and can afford the overhead of neural pipelines.
SimplePyBLE provides cross-platform Bluetooth Low Energy (BLE) bindings for Windows, macOS, and Linux, with both synchronous and asynchronous APIs for discovering and communicating with BLE devices.
However, verify upfront whether your intended use qualifies as non-commercial under BUSL-1.1 terms, or budget for a commercial license if building proprietary…
Solves package dependency resolution using Boolean satisfiability (SAT) solving, determining which package versions satisfy a set of constraints.
However, the explicit prototype status and 498-day gap since the last release suggest it is not actively maintained; use it for research, prototyping, or custom…
Simplify LineStrings using the Ramer–Douglas–Peucker or Visvalingam-Whyatt algorithms, reducing coordinate counts while preserving geometry shape.
An async Python interface to the SimpliSafe API that lets you query system state, sensor data, and control your SimpliSafe security system from Python code.
Install it if you're building home automation or monitoring tooling around SimpliSafe.
SimPy is a process-based discrete-event simulation framework that uses Python generator functions to model active components and shared resources, allowing simulations to run as fast as possible, in real time, or by manual stepping.
Install it if you need to model systems with interacting processes and shared resources; skip it if your problem is continuous simulation or fixed-step modeling.
SimSIMD provides SIMD-optimized kernels for computing vector distances, dot-products, and similarity measures across multiple data types and precisions, with support for spatial, probabilistic, and bit-level operations.
Install it if vector similarity or distance computation is a measurable bottleneck in your application.
Builds Singer-compliant data extraction taps and loading targets with less boilerplate code than writing them from scratch.
Install it if you need to build Singer-compliant data connectors or integrate with Meltano pipelines.
Extracts your package version from pyproject.toml or other config files and makes it available in Python code, eliminating the need to duplicate version strings.
However, maintenance is dormant, so consider whether you are comfortable with a stable-but-not-actively-maintained tool.
Provides single-dispatch generic functions—a decorator-based mechanism to define functions that behave differently based on the type of their first argument—backported from Python 3.4's functools module for use on older Python versions.
Provides a DB-API 2.0 compatible Python interface to SingleStore, a distributed SQL database, supporting both MySQL protocol and HTTP connections with optional C acceleration for faster data reading.
Install it if you need a Python driver for SingleStore or are building vector search or real-time analytics applications on that platform.
Provides a decorator that enforces singleton pattern on classes while preserving direct access to the underlying class for unit testing via the `__wrapped__` attribute.
Sinter performs fast Monte Carlo sampling of quantum error correction circuits, using stim to generate samples and decoders like pymatching to predict logical errors from detector data.
Modifies the input and output shapes of ONNX model files, allowing you to adapt pre-trained models to different batch sizes, dimensions, or symbolic shape parameters via CLI or Python API.
SIP generates Python bindings for C and C++ libraries by processing specification files and creating compiled extension modules that expose C/C++ code to Python.
Install it if you need to generate Python bindings for C/C++ libraries or if you are using a package (like PyQt) that depends on it.
Provides a Python implementation of SipHash, a keyed hash function optimized for speed on short messages, following the hashlib API.
Provides a C-based SipHash-1-3 and SipHash-2-4 implementation with a hashlib-compatible interface and streaming support, returning digests as bytes or 64-bit signed integers.
However, the aging maintenance status (346 days since last release) and unclear license metadata warrant a quick review of your licensing requirements before committing.
siphashc provides a Python binding to the SipHash-2-4 cryptographic hash function, implemented as a C extension for performance.
Runs inference tests on ONNX models using TensorRT, CUDA, OpenVINO, or CPU execution providers, measuring performance and validating model outputs.
However, note that the package is aging (last commit 341 days ago) and you will need to separately install the execution provider libraries (TensorRT, OpenVINO, etc.)…
Implements EIP-4361 Sign-In with Ethereum for parsing, verifying, and serializing authentication messages signed with Ethereum private keys.
Install it if you need Ethereum-based authentication in a Python application.
Six provides utility functions to write Python code that runs on both Python 2.7 and Python 3.3+, smoothing over language differences between the two versions.
Reads, writes, and processes video files using FFmpeg as its backend, providing video I/O and quality metrics (NIQE, BRISQUE, SSIM, PSNR) built on numpy and scipy.
Analyzes skeleton (thin object) images to extract and characterize their structure, connectivity, and morphological properties using Python.
skfolio is a Python library for portfolio optimization and risk management that integrates with scikit-learn to build, tune, cross-validate, and stress-test portfolio models using a unified interface.
Install it if you need portfolio optimization; skip it if you only need basic mean-variance calculations or prefer a different API.
Skforecast is a Python library for time series forecasting that works with any scikit-learn compatible estimator, providing tools for feature engineering, model selection, hyperparameter tuning, and backtesting.
Install it if you need to forecast time series with scikit-learn compatible estimators.
Python bindings for Google Skia's Path Ops module, enabling boolean operations (intersection, union, difference, xor) on vector paths.
Validates, parses, and generates prompt-compatible XML from Agent Skills—a standardized format for packaging AI agent capabilities as reusable skill modules.
However, the Alpha status and aging maintenance signal mean the format and library are still evolving; verify that Agent Skills adoption aligns with your agent…
A linter for AI agent instruction files that detects structural errors, vague language, contradictions, security risks, and configuration problems in agent skills, plugins, and coding assistant context.
Install it if you maintain agent skills, plugins, or AI coding assistant context files.