PyCoder’s Weekly

Issue #752: Dict Performance, Hypothesis, Lazy Imports, and More (2026-09-15)

2026-09-15T19:30:00+00:00

#752 – SEPTEMBER 15, 2026
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Sets and Dictionaries Can Have Quadratic-Time Performance

A rough first approximation is that a dict has O(1) performance, but that only holds true for smaller containers. This article explores the performance limits of sets and dictionaries.
DANIEL LEMIRE

Stop Writing Edge Case Tests. Use Hypothesis Instead

Introduction to property-based testing in Python with Hypothesis. Move from ‘what input should I test?’ to ‘what invariant should always hold?’
PEYTON GREEN • Shared by Anonymous

Tired of Getting Blocked While Scraping the Web?

ScrapingBee handles proxies, browsers, anti-bot systems, and retries so you can focus on your data. Get clean Markdown, JSON, or HTML from the web with up to a 99,9% success rate. ScrapingBee is SOC 2 Type II and GDPR compliant, and trusted by 4,000+ developers. Try ScrapingBee With 1,000 Free Credits
SCRAPINGBEE sponsor

Python 3.15 Preview: Lazy Imports

Learn how Python 3.15 lazy imports work, how deferring heavy modules cuts your app’s startup time, and which imports still have to stay eager.
REAL PYTHON

Articles & Tutorials

Nifty Django Feature: Q() Objects

Django’s ORM includes the filter() method for returning a subset of rows in the database. Anything you can do with filter() you can do with a Q() object, which encapsulates the filter’s arguments. Since it is an object you can dynamically create and manage filters in your code.
TIM SCHILLING

Profile on Guido van Rossum

The BBN Times has done a profile piece on Python’s creator Guido van Rossum. It covers his background, the creation of Python, and how he helped shepherd the language to its current state.
FELIX YIM

Making a Python Interpreter in 1024 Bytes

Austin challenged himself to make a tiny subset of Python in C. It isn’t quite Python, but bares a resemblance and with a little code golf he built something quite small.
AUSTIN Z. HENLEY

Reading `dict` Once Deoptimizes Attribute Access

The usual explanation for why hoisting attributes out of a loop is faster has been wrong since CPython 3.11. Read about what more recent interpreters do.
TIMOFEI IVANKOV • Shared by Timofei Ivankov

An Effective Python Development Environment

Choose a Python development environment that helps you get coding. Find tutorials and courses on editors, uv, virtual environments, and useful tools.
REAL PYTHON

Quiz: An Effective Python Environment

REAL PYTHON

How Hard Is It to Find a Remote Python Data Job?

Piotr analyzed 88,975 Hacker News job posts from 2012 to 2026. The board shrank, remote work peaked, pay became clearer, and senior roles took over.
PIOTR PŁOŃSKI

Python Timer Functions

Learn how to time your Python code with the time module, then build a reusable Timer class that works as a context manager.
REAL PYTHON course

Quiz: Python Timer Functions

REAL PYTHON

Prototyping a New CLI for Wagtail

Wagtail 8 introduced a new API which has allowed devs to create a command line tool for interacting with a Wagtail CMS.
THIBAUD COLAS

Teaching NumPy’s `ufuncs` New Tricks

Iason recently did an internship working on NumPy internals. This post talks about what he accomplished.
IASON KROMMYDAS

Projects & Code

django-ox: Database Based Django Task Backend

GITHUB.COM/OXPULL

import-linter: Define and Enforce Rules for Imports

GITHUB.COM/SEDDONYM

Plotext 6: Plot Data, Images and Video in the Terminal

GITHUB.COM/PICCOLOMO • Shared by Savino Piccolomo

deployproof: AST Mutation Testing & Credential Scanning

GITHUB.COM/SVSPRAVEEN

dbmask: Discover & Mask Sensitive Data in Databases

GITHUB.COM/SEALANDSEACAT • Shared by Siyuan Feng

Events

Weekly Real Python Office Hours Q&A (Virtual)

September 16, 2026
REALPYTHON.COM

PyCon Cameroon 2026

September 17 to September 20, 2026
PYTHONCAMEROON.ORG

PyData Bristol Meetup

September 17, 2026
MEETUP.COM

Python Leiden User Group

September 17, 2026
PYTHONLEIDEN.NL

PyLadies Dublin

September 17, 2026
PYLADIES.COM

Happy Pythoning!
This was PyCoder’s Weekly Issue #752.
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Issue #751: Profiling, From pandas to Polars, NotImplemented, and More (2026-09-08)

2026-09-08T19:30:00+00:00

#751 – SEPTEMBER 8, 2026
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Profiling and Making Apps Fast by Default

How do you plan for the performance of your Python applications? What does a performance budget entail, and where should you spend your resources? This week on the show, we speak with Den Odell about his new book “Fast by Default: Practical Performance Engineering.”
REAL PYTHON podcast

Migration Strategies for Going From `pandas` to `Polars`

How to scope a pandas to Polars migration, from a single performance-sensitive section to the whole pipeline, and how to execute a full migration by hand or with an LLM.
THIJS NIEUWDORP

The Top Open-Source Code Reviewer on Code-Review-Bench

PR-AF places #2 of 42 overall on Martian’s Code-Review-Bench, ahead of CodeRabbit, Copilot, and Devin. Roughly 3x more valid findings than the commercial tools, at ~10x lower cost per review. Verified findings only. Apache 2.0, self-hosted, runs on any open or closed model. Star & Deploy →
AGENTFIELD sponsor

When to Use `NotImplemented`

When should you return NotImplemented from a dunder method? Why not return False or raise an exception instead?
TREY HUNNER

Articles & Tutorials

Build a Plugin Architecture With a Pydantic and FastAPI

Learn how to build a plugin architecture across service boundaries using a shared Pydantic API contract. This article walks through registration-time validation, FastAPI endpoints, ownership and authorization decisions, and continuous health checks for independently deployed services.
PATRICKM.DE • Shared by Patrick Müller

Metadata Requests No Longer Tracked as PyPI Downloads

Previously, requests for information about a package on PyPI got counted as a download in the package statistics. This was recently changed to more accurately account only for the downloads of wheels, tar balls, and zip files. This article explains the change.
PYPI.ORG

Which AI Tools Are Worth Using? A Live Course for Python Devs With “No Time to Try Them Out”

Stop stressing over every new AI coding tool release: in one live session on September 12 you learn which categories are worth it, which to skip, and a 60-second test that settles every launch after that. Reserve Your Spot →
REAL PYTHON sponsor

Build Your Own Face Recognition Tool With Python

In this tutorial, you’ll build your own face recognition command-line tool with Python. You’ll learn how to use face detection to identify faces in an image and label them using face recognition. With this knowledge, you can create your own face recognition tool from start to finish!
REAL PYTHON

How to Fix ‘NoneType’ Object Has No Attribute Errors

When Python throws AttributeError: ‘NoneType’ object has no attribute ‘x’, it reads like the interpreter is being deliberately unhelpful, but it’s actually telling you something precise: a variable you expected to hold an object turned out to be None.
SYSTEM CRAFT PRESS • Shared by Bob Morrison

Primer on Python Decorators

In this tutorial, you’ll look at what Python decorators are and how you define and use them. Decorators can make your code more readable and reusable. Come take a look at how decorators work under the hood and practice writing your own decorators.
REAL PYTHON

Type Checking Could Be the Guardrail Your Agent Is Missing

Coding agents write a lot of Python, and they write it fast. Having your agent call a typechecker can prevent common type bugs creeping in. Pyrefly is an open-source typechecker built in Rust that’s fast enough to keep up with your agent’s inference.
PYREFLY TEAM sponsor

Testing Async Python Without Losing Your Mind

Async Python testing patterns that actually work: event loop scope, async fixture lifecycle, and the specific pytest-asyncio / anyio patterns that break under default assumptions.
DEV.TO • Shared by Anonymous

Storing Django Static and Media Files on Cloudflare R2

This tutorial shows how to configure Django to load and serve up static and media files, public and private, via Cloudflare R2 an AWS S3-like cloud storage service.
NIK TOMAZIC

Analysis Paralysis Sucks

Junior developers don’t start because they don’t know enough. Senior developers don’t start because they know too many things that could go wrong. Both are stuck.
KEVIN RENSKERS

Async Programming in Python: From Generators to `asyncio`

Learn how Python async programming works. Write async functions with async and await, and run slow I/O operations concurrently with asyncio.
REAL PYTHON

Why OOP Exists

Learn the fundamental principles behind Object Oriented Programming (OOP) and how that connects to the Python syntax for class definition.
RODRIGO GIRÃO SERRÃO

Python 3.15 Preview: UTF-8 by Default

Preview the Python 3.15 UTF-8 default: see what changes, try it on a pre-release, and keep your file I/O portable across every platform.
REAL PYTHON

Quiz: Python 3.15 Preview: UTF-8 by Default

REAL PYTHON

Optimal Seating on the Airbus A380

Mark analyzes the results from a paper that determined the optimal seating arrangement on an Airbus A380.
MARK LITWINTSCHIK

Projects & Code

shedskin: Restricted-Python-to-C++ Transpiler

GITHUB.COM/SHEDSKIN

A Browser DOM, in Python!

GITHUB.COM/BYTEFACE • Shared by byteface

pandas-silent-bugs: 182 Examples Where `pandas` Is Wrong

GITHUB.COM/THIBAUDLEPAN77-SVG • Shared by Thibaud Lepan

mitti: Next-Gen ASGI Framework

GITHUB.COM/GRANDIMAM

jsonstore: Django JSONField Data as Virtual Model Fields

GITHUB.COM/VIEWFLOW

Events

Weekly Real Python Office Hours Q&A (Virtual)

September 9, 2026
REALPYTHON.COM

Python Atlanta

September 10 to September 11, 2026
MEETUP.COM

PyDay Boyacá 2026

September 12 to September 13, 2026
PYDAY.CO

DFW Pythoneers 2nd Saturday Teaching Meeting

September 12, 2026
MEETUP.COM

DjangoCologne

September 15, 2026
MEETUP.COM

PyCon Cameroon 2026

September 17 to September 20, 2026
PYTHONCAMEROON.ORG

Happy Pythoning!
This was PyCoder’s Weekly Issue #751.
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[ Subscribe to 🐍 PyCoder’s Weekly 💌 – Get the best Python news, articles, and tutorials delivered to your inbox once a week >> Click here to learn more ]

Issue #750: State of Django, PSF Elections, Python 3.15, and More (2026-09-01)

2026-09-01T19:30:00+00:00

#750 – SEPTEMBER 1, 2026
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The State of Django 2026: Boring Is So Back

A summary of this year’s State of Django report which draws on responses from nearly 3,500 developers across more than 40 countries: from students in their first year to veterans with decades of experience.
WILL VINCENT

2026 PSF Board Election Interviews

This is a collection of interviews of the various candidates running for the Python Software Foundation Board. Many of the posts also include links to AMA sessions.
PYTHON SOFTWARE FOUNDATION

Python 3.15 Preview: Sampling Profiler

Explore Python 3.15’s new sampling profiler and learn low-overhead profiling of scripts, threads, and live production processes.
REAL PYTHON

Quiz: Python 3.15 Preview: Sampling Profiler

REAL PYTHON

RISC-V Is Now Officially Supported by CPython

PYTHON.ORG

PEP 843: Export Statement for DRY Re-Exports (Draft)

PYTHON.ORG

Articles & Tutorials

The Python Community’s Institutional Response to the Astral Acquisition Has Begun

Brett Cannon posted on discuss.python.org (March 23): a PEP is coming, the python/prebuilt-cpython repo already exists, and the PSF has been building an official prebuilt relocatable CPython distribution since October 2025. Covers what’s actually being built, what it means for uv/ruff/python-build-standalone, and why the Astral upstream patches and PSF alternative aren’t in conflict.
DEV.TO • Shared by Anonymous

Unsubscribe Links Without a Login: Django Signing

Django has a signing module that makes it easy to build an unsubscribe link that works with no login and no session: token = signing.dumps(recipient.pk, salt=UNSUBSCRIBE_SALT). The token itself is the credential, and it ships with Django out of the box.
BOB BELDERBOS • Shared by Bob

AI Coding Tools for Python Developers: What’s Actually Worth Using Right Now

Join the one-day live course this Saturday, September 12. Get live demos of every category of AI coding tool, a verdict on each, and a 60-second test you can run on whatever launches next. Examples are in Python, and no prior AI experience is required. Reserve your seat here →
REAL PYTHON

CMS With AI, Not AI CMS: Wagtail 8.0’s New API

Wagtail 8 includes a new API built on Django Ninja and Pydantic, to automate common admin tasks with and without agents. 50+ operations derived from projects’ existing Python/Django code, mimicking the admin panel but via endpoints and an official CLI.
WAGTAIL.ORG • Shared by Thibaud Colas

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