Aspect-oriented programming, monkey-patch and decorators library

https://github.com/ionelmc/python-aspectlib

Astor allows easy manipulation of Python source via the AST

https://github.com/berkerpeksag/astor

Abstract syntax tree for Python with inference support

https://github.com/PyCQA/astroid

Abstract syntax tree for Python with inference support

https://pylint.readthedocs.io/projects/astroid/en/latest/ https://github.com/pylint-dev/astroid

Annotate AST trees with source code positions

https://pypi.org/project/asttokens/ https://github.com/gristlabs/asttokens

AST unparser for Python

https://github.com/simonpercivall/astunparse

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

High performance PostgreSQL Client Library for Python/asyncio

https://github.com/MagicStack/asyncpg/

Enhance unittest for testing asyncio libraries

https://github.com/Martiusweb/asynctest

AtomicLong type using CFFI

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

Atomic file writes library

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

Very simple decorator and function of module's all

https://public.readthedocs.io/

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

Generate email authentication headers

https://github.com/ValiMail/authentication-headers

Python module for RFC 5451 Authentication-Results headers

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

Create a command-line program from a function

https://github.com/Lucretiel/autocommand

Python interface to the Avahi mDNS system

https://www.avahi.org/

Library that transform SAM templates into AWS CloudFormation templates

https://pypi.org/project/aws-sam-translator/

AWS X-Ray SDK for Python

https://github.com/aws/aws-xray-sdk-python

Universal Command Line Interface for Amazon Web Services

https://aws.amazon.com/cli/

Common runtime for AWS Python projects

https://github.com/awslabs/aws-crt-python

Python API to access data from the Google Fonts variable fonts axis registry

https://github.com/googlefonts/axisregistry

Backblaze B2 SDK

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

Collection of tools for internationalizing Python applications

http://babel.pocoo.org/

Abstract interface to font source files based on fontParts

https://github.com/simoncozens/babelfont

Function decoration for backoff and retry

https://github.com/litl/backoff

Shared namespace shim for py-backports.* ports

Backport of CPython tarfile module

https://github.com/jaraco/backports.tarfile

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/

HTML/XML Parser for Python

https://www.crummy.com/software/BeautifulSoup/

Extract semantic information about static Python code

https://github.com/serge-sans-paille/beniget

Python bindings for Oracle Berkeley DB

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

Bezier curve manipulation library

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

Lightweight pure Python package to check if a file is binary or text

https://github.com/audreyr/binaryornot

Python Bitcoin Tools

https://github.com/vbuterin/pybitcointools

Uncompromising code formatter

https://github.com/psf/black

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/

Create and parse boolean expressions and create custom boolean DSL

https://github.com/bastikr/boolean.py

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