urllib3

urllib3 is a Python HTTP client library that provides a robust, user-friendly interface for making HTTP and HTTPS requests. It is widely used as a lower-level component in other libraries, and is the underlying HTTP layer for the requests library. The project emphasizes reliability, efficiency, and a clean API for managing connections.

Key features include a thread-safe, feature-rich connection pool with PoolManager and HTTPS support, which allows reuse of connections across requests to improve performance. It offers configurable retries and backoff strategies through the Retry class, as well as timeouts via the Timeout class. urllib3 supports streaming requests and responses, enabling handling of large payloads without loading them entirely into memory. It provides client-side SSL/TLS verification and allows customization of SSL contexts and certificates, giving developers control over security settings. The library also supports proxies via ProxyManager and provides utilities for URL parsing and header handling.

Usage typically involves creating a pool-based manager and issuing requests through methods like request or urequest. The response object exposes attributes such as status, data, and headers, and urllib3 supports streaming bodies to handle large transfers efficiently. Its modular design makes it suitable for building higher-level HTTP clients or integrating into larger Python applications where robust connection handling and error-handling are important.

Licensing and ecosystem: urllib3 is open-source software released under the Apache License 2.0. It is actively maintained by an open community of contributors and is a core dependency for many Python projects. Its widespread adoption and stable interface make it a standard choice for performing HTTP operations in Python, either directly or as a dependency of higher-level libraries.