Fast and easy to use stand-alone template engine

https://jinja.palletsprojects.com/en/3.1.x/

Piecewise linear interpolation in multiple dimensions

https://github.com/LettError/MutatorMath

OpenGL (and related library) interface for Python

http://pyopengl.sourceforge.net/

Iconic fonts in PyQt and PySide applications

https://github.com/spyder-ide/qtawesome

Abstraction layer on top of the various Qt bindings

https://github.com/spyder-ide/qtpy

Store passwords using the SecretService DBus API

https://pypi.org/project/SecretStorage/

Small text templating language

https://pythonpaste.org/tempita/

ACME protocol implementation in Python

https://github.com/certbot/certbot/tree/master/acme

Simple DNS resolver for asyncio

https://pypi.org/project/aiodns/

FTP client/server for asyncio

https://aioftp.readthedocs.io/

Async http client/server framework (asyncio)

https://github.com/aio-libs/aiohttp

Python library for accessing PostgreSQL database using asyncio

https://github.com/aio-libs/aiopg

Python asyncio (PEP 3156) Redis client library

https://github.com/aio-libs/aioredis

AsyncIO bridge to the standard sqlite3 module for Python 3.5+

https://pypi.python.org/pypi/aiosqlite

Modified Kr Sphinx theme

https://github.com/bitprophet/alabaster

Namespace control and lazy-import mechanism

https://bitbucket.org/hpk42/apipkg

Python module for determining platform-specific dirs

https://github.com/ActiveState/appdirs

Secure Argon2 password hashing algorithm

https://argon2-cffi.readthedocs.io/

Better dates and times for Python

https://github.com/arrow-py/arrow

ASN.1 library with a focus on performance and a pythonic API

https://github.com/wbond/asn1crypto

Abstract syntax tree for Python with inference support

https://github.com/PyCQA/astroid

Tiny library to add async generators to Python 3.5

https://pypi.org/project/async_generator/

Timeout context manager for asyncio programs

https://github.com/aio-libs/async-timeout

Reference implementation of PEP 3156 (Asynchronous IO)

https://github.com/python/asyncio

AtomicLong type using CFFI

https://pypi.org/project/atomiclong/

Atomic file writes library

https://github.com/untitaker/python-atomicwrites

Python API for the D-BUS based SPI framework

https://gitlab.gnome.org/GNOME/pyatspi2

Python attributes without boilerplate

https://github.com/python-attrs/attrs

Python module for RFC 5451 Authentication-Results headers

https://launchpad.net/authentication-results-python/

WebSocket client & server library, WAMP real-time framework

http://autobahn.ws/python

Backblaze B2 SDK

https://github.com/Backblaze/b2-sdk-python

Collection of tools for internationalizing Python applications

http://babel.pocoo.org/

Shared namespace shim for py-backports.* ports

Tools to help document botocore-based projects

https://github.com/boto/bcdoc/

Modern password hashing for your software and your servers

https://github.com/pyca/bcrypt/

Library for working with BDF font files

https://gitlab.com/Screwtapello/bdflib

Session and Caching library with WSGI Middleware

https://beaker.readthedocs.io/en/latest/

Bezier curve manipulation library

https://github.com/simoncozens/beziers.py

Python Bitcoin Tools

https://github.com/vbuterin/pybitcointools

Easy safelist-based HTML-sanitizing tool

https://github.com/mozilla/bleach

Thin wrapper around terminal coloring, styling, and positioning

https://github.com/erikrose/blessings

Fast, simple object-to-object and broadcast signaling

https://pythonhosted.org/blinker/

Boolean operations on paths

https://github.com/typemytype/booleanOperations

Deduplicating backup program

https://pypi.org/project/borgbackup/

Python interface to Amazon Web Services

https://github.com/boto/boto/

AWS SDK for Python

https://github.com/boto/boto3

Low-level, core functionality of boto 3

https://github.com/boto/botocore

Python binding to the Brotli library

https://github.com/python-hyper/brotlicffi

Python extension module for BerkeleyDB 4+

https://www.jcea.es/programacion/pybsddb.htm

Continuous Integration Framework

https://buildbot.net